Infinity upgrade at exchange appears to have kille...

Question

Hi all, 
I know there are plenty of threads about slow connection speeds and I was rather reluctant to start another, but having previously spent the best part of an afternoon on the phone purely to get an email password reset, I thought I would try for some help here before braving the call centres again! 
Anyway, as the title  suggests, at the end of January I received an email telling me that my local exchange (Dartford, Kent) was being upgraded to this "infinity" malarkey, there may be a window of a few minutes where my connection went down and that I would need to leave my hub on and let it settle down for a week or so once the upgrade was complete. "No problem" thought I, "whilst I'm quite happy with my option 3 package, it's good to know I can probably upgrade if I want to in the future." Plus, the email seemed to suggest that even if I didn't upgrade I still might see an increase in speed. 
You might appreciate that I am rather peeved therefore to see that since the upgrade was completed in mid February, my downstream connection has dropped from a perfectly adequate 7/8,000kbps to a pretty much useless and rather flakey 3,000kbps.
Now I know there are people who have far worse connections than this, but when I have been paying a premium BT price for a nice, stable and reasonably fast connection for the last four years I'm not overly impressed with the idea of continuing to pay that premium price for a connection that can no longer even reliably stream a programme from Iplayer, let alone cope with that radical 21st century idea of two users trying to access the Internet at the same time!
I should stress that there have been no changes whatsoever to the setup at my end. The router is connected to the master socket in exactly the same way as it has been for the last four years. That said, if anyone has any suggestions as to how I can convince BT's software that my line is still capable of handling the throughput it has managed quite happily for the last four years, I will be happy to try them. Curiously, a friend who lives nearby had a similar problem which was miraculously solved once he agreed to sign up for a new contract. I won't be putting on the tinfoil hat just yet, but the thought does occur...
If anyone can offer some thoughts, suggestions etc... On what I might do to return my connection to what it was previously, I would be tremendously grateful. 
Thanks
What details I have managed to extract from my hub are posted below. 
Uptime: 7 days, 5:04:51
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 728 / 3,067 (previously in the 7,000 region and regularly pulling stuff down from Steam at 800 kBps)
Data Transferred (Sent/Received) [MB/GB]: 929.03 / 25.61
Output Power (Up/Down) [dBm]: 9.5 / 0.0
Line Attenuation (Up/Down) [dB]: 18.0 / 31.5
SN Margin (Up/Down) [dB]: 7.5 / 19.5
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 16 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 1,029
HEC Errors (Up/Down): 0 / 1,005
Line Profile: Fast
Uptime: 7 days, 5:04:51Modulation: G.992.5 annex ABandwidth (Up/Down) [kbps/kbps]: 728 / 3,067Data Transferred (Sent/Received) [MB/GB]: 929.03 / 25.61Output Power (Up/Down) [dBm]: 9.5 / 0.0Line Attenuation (Up/Down) [dB]: 18.0 / 31.5SN Margin (Up/Down) [dB]: 7.5 / 19.5Vendor ID (Local/Remote): TMMB / IFTNLoss of Framing (Local/Remote): 0 / 0Loss of Signal (Local/Remote): 0 / 0Loss of Power (Local/Remote): 0 / 0Loss of Link (Remote): 0Error Seconds (Local/Remote): 16 / 0FEC Errors (Up/Down): 0 / 0CRC Errors (Up/Down): 0 / 1,029HEC Errors (Up/Down): 0 / 1,005Line Profile: Fast

Answer 1

Hi Geoff, 
I could have sworn the email mentioned the exchange being upgraded to infinity but I have long since deleted the relevant email and from what you have said, and some further research on the Internet, I am coming round to the conclusion that I was mistaken and that it was actually an upgrade to ADSL2. Either way it has still put the mockers on my connection speed! 
I've tried the quiet line test and all seemed pretty **bleep** quiet to me ( I couldn't hear a thing and neither could my better half), unfortunately the BT speedtest refuses to work and simply tells me that it is unable to perform a test. I've tried it a number of times since you first suggested it last night. 
There's nothing obvious to suggest the problem is at my end. I've tried swapping filters, checking there were no loose connections etc, but all seems to be pretty much as it was before the problem started. I guess I will have to bite the bullet and brave the help desk. I guess I should book a days leave from work to make the call...
One final question if I may? I have been toying with the idea of switching providers recently. I'd rather stay with BT because, as I said previously, whilst they are expensive, I value the good service I have generally received to date over saving a few beer tokens each month, but if I am given the run around, as I seems to be the norm when I contact tech support, I may just bite the bullet and go. If this does turn out to be a problem at the exchange am I likely to see the same problem even when switching provider? 
Thanks to all that have taken the time to comment and offer assistance, it is genuinely appreciated.