Working Line Takeover - cancelled by previous tena...

Question

I moved into a rental property last week.  The following is the story of how the move went as far as my BT phone and internet services go:
5 September 11:02
I called BT to arrange home move for 26 September
I was told there was an active BT line there and they would contact the current account holder to arrange the closure of the existing account.
I was told that the line takeover would occur whether they were able to contact the current account holder or not.  They would force the takeover if they had to.
I was told I would receive an email detailing my order and also a letter in the post.
I was told to keep my current router and hook it up at the new property when I move in.
15 September 09:36
I had not received an email or a letter regarding my order.
I called BT to confirm things were still on schedule and was assured that there were no issues and that they didn't know why I hadn't received an email and that the letter may have gone to the new address but not to worry, I would have service on the 26th at my new address.
26 September
My internet was shut off at my old address but I noticed that I still had a dial tone on my phone.
I connected my equipment at my new home. The phone seemed to be working but the internet was not. I thought nothing of it as it might just not be active yet and I was busy with moving house.
There was no mail from BT addressed to me.  There was a letter addressed to the new occupant trying to sell BT services so it seems likely that BT new there was a move out/in.
27 September
Internet still not working.
Incoming calls to my number were not working.
I called my mobile from the home phone at the new address - caller id number was not mine. This suggested the line takeover had not happened.
I tried entering my phone number in the BT website for tracking faults and was told to enter a valid BT phone number.
29 September 7:31
I called BT to report the issue and was told she would have to call me back after 9.
Received call back at 9:04
They told me that it looked like my order was complete from their side so they would have to cancel and replace the order.
They indicated that I would be notified within 24-48 hours by the order replacement team.
I explained that this delay was not acceptable as a few weeks out of every year I provide out of hours support for 999 services and need my internet running - this happens to be one of those weeks.  I understand that I am a residential customer and don't have the privileges of a business account but I thought that this information might motivate BT to prioritize my case - she seemed to understand this and told me that they couldn't give me a better window for being contacted but that the fix shouldn't take the full amount of time so I should keep checking my internet service.
30 September ~13:30
Internet service still not working and the phone line is still active with the previous persons details.
Called BT to check on the status.
I was told that what had happened was that the previous tenants had cancelled the line takeover and that is why my order was cancelled and had to be replaced.
I was given no explanation as to why I wasn't notified of this ahead of my move.
I was then told that it could take up to 5 days for me to hear back and was given no explanation as to how this had changed from 24-48 hours into 5 days. Also, no apology for this.
I was told that the only people who could give me an update were the Order Replacement department and that there was no way I could contact them. I just have to wait for them to contact me. All she could do was add a note to my request.
I tried to persist that there must be a way for someone to escalate this further but she was insistent that nobody in her call centre could actually talk to anyone from Order Replacement.
She indicated that she had added a note to my request and that me calling again would be a waste of time as nobody there could give me any more information.
I was assured I would not be billed for any of the time I am without service. I will be watching my direct debit to ensure this is the case.
I am astounded by the poor customer service and the conflicting information I am receiving.
Why was I not notified that there could be a problem with the line takeover?
Why was there no communication to me about my order being cancelled?
Why am I being given different information from different support people as to how long I can expect this to take? Why can a person who is no longer a resident of a property control the phone line at that property? They don't live here anymore. I do.
Does anybody have any suggestions on how I can reconcile this more quickly?  I've called my estate agent to see if they can contact the previous tenants with regard to canceling their account to hopefully get the ball rolling from that side but I guess I'm not totally sure if the line belongs to the previous tenant or if it belongs to the landlord.  I would think if it belonged to the landlord my estate agent would be aware of this and would have let me know when I questioned them about my concerns about BT getting this done smoothly.
I am from Canada and a phone number is a very portable thing for a renter - it travels with you when you move and you would never leave a phone line active at a previous property.  A landlord would also not leave a phone line active at their rental property in most cases unless they were only letting the property for a very short term.
If any mods see this, please contact me and let me know if you can help.
Thanks

Answer 1

I contacted the mods on 30 September as requested in this thread.  I received no contact from them.
On 1 October, having not received a followup call from my previous attempts, I called again to try to get an update.  This time I must have chosen a different menu option as I was given the option to not wait in the queue and have an automatic call back when it was my turn.  I agreed to this providing my mobile number.  In about 5-10 minutes I received the call back.
The person who I spoke with had to transfer me to a different department - he didn't say which one.  After waiting on hold for a while I spoke with a man who actually showed concern that I hadn't been called back.  He had me hold while he spoke with his manager.  When he came back on the line he promised me that I would hear from BT on Friday and that this would address my issue.
Friday 3 October came and I did finally get a promised call back, though they indicated it was in response to an email I had sent though I hadn't sent any emails.  I was informed that an order had not previously been re-placed with Open Reach but now one had.  The activation date was set for 14 October but I was assured that once Open Reach accepted the order BT would contact them to get this activation moved up.  I was told I would get a call back "tomorrow" with an update.
6 October came and I had not yet received an update so I called BT again to ask for one only to be told that all of their systems were down in the call centre and I would have to call back in 4 hours.  I insisted that I shouldn't have to keep chasing this so she took my mobile number and told me I would receive a call back later that day.  This did not happen.
7 October I called once again hoping to get an update.  Initially I was told that I would hear from the Offline Team today.  I asked to speak to them now.  The calltaker put me on hold for quite a while and when she came back on she told me that the order had been placed with Open Reach and that it was set for 14 October.  Information I already had.  I asked to speak with her supervisor and after being on hold again for quite some time the call was disconnected.
I am hoping to but not counting on hearing from the Offline Team today.  I leave for Germany for 2 weeks on 12 October and I don't want to leave my family with this unresolved but I seem to be getting little help from BT.
I am also yet to get any explanation as to why I was never told about my order being cancelled, why I never received any confirmation emails, why I can't see an order on my BT account, why when I type my phone number into the Check Service Status tool on the BT Help website it says "Please enter a valid BT phone number. Your number should start with 01 or 02 and contain 10 or 11 digits.".
I am going to try the contact the mods thing again and see if it helps.  I am getting really frustrated with the lack of service.