Stuck Order since 27 March and now a cancelled one...

Question

So on 27 March I signed up for a £10 contract discounted to £5 as I have broadband. 
No sim arrived - order number wasn't a VOL number but BTCZZ.... which on reflection means an order that has gone wrong!
By 1st April I called because still not received, spoke to someone who said they would reorder a sim - note I am now paying for the contract..........
Replacement sim arrives Thurs before Easter, but can't activate it because BT system now seems to have a issue with this contract. Advised by nice woman that it'll all be ok by tomorrow.
Good Friday - now on holiday and still the sim not working. This goes on and on and on until on 10th April someone at BT (don't let the customer know what's going on) decides to put a new order on for a new sim - Yeah great - oh wait a minute not great as the wrong size sim is sent!!
12 April order confirmation that the sim I didn't receive (eh I received both just one don't work the other is too big) has now been blocked.
14 April new sim for new contract surprising the right size arrives. Still BT don't really want to do much with it because they're not really sure whether to activate it, hey hum few days of looking at order on system advising me to wait......
Eventually the second contract is activated, now at this time I think I don't want to port the old number over because I'd rather get the sorry mess sorted before doing so but nice man at BT says yes do it, we've got this one going so lets get the right number on it.
So by 16th April the ported number is now on the working contract and we agree that the other contract needs clearing off. However BT send me a bill now for the part months and the full months on both contracts. So I say hey this isn't fair why should I pay for something I cant use and also for the second contract that I only was able to use the day of the bill. Nice man says well I'll put a credit on your account for the whole amount of this sorry mess.
Great says I.
Computer says no!
Whole bill is taken by DDR, credit stays languishing at BT's place, my money goes to whacking great corporation that made the mess.
So agree with nice man that they can look after my money for a month and hopefully - I mean who'd think this mess will honestly go on for another month, c'mon ha ha nothing so daft could possibly happen....
So 16 May my new bill comes - yes the credit for last month is now allowed out into the billing system, but then hang on a minute, what's this, the non working contract that has been ill since the day of inception, still manages to sneak onto the bill!
Oh for goodness sake thinks I, still I'm sure they'll credit that and my nice man will call and tell me all is well with their profits and my money won't have to spend time in BT'sville.
Oh no, instead nice man is on holiday so stupid person at BT thinks I know I'll cancel the working contract, the one with the customers ported phone number, oh how they'll laugh.
Except I'm not laughing anymore. 

Answer 1

Since giving the direct number nice man has never answered, and also claimed (perhaps someone deleted the message) not to have received 1 message I was able to leave, this has been going on weeks, over the last 7 weeks I have been extremely fair. 
I'm not about to put the full ins and outs of this sorry mess, BT are now very aware of the problem and I have a direct phone number and email for the person now dealing with it - which I have absolutely no intention to share, don't ask if your're looking for a solution - and she hopefully will now ensure the whole sorry mess is resolved in full not just in part, as the partial resolution was the root cause for them cancelling the contract - I had 2 one that never worked and one that did, they chose to cancel the wrong one, but the wrong one should have been cancelled weeks ago. (and indeed an attempt was made to cancel on 22 April but it seems that also went wrong)
My main issue is that this is a phone for a vulnerable person and it was totally unacceptable to cancel the contract with 14 minutes notice - BT have to put in process the ability for mistakes to be easily sorted.
I hope that BT will take note of the fact that they do need to have some sort of critical resolution procedures, or an effective method of avoiding such a potentially catastrophic event in future.
Any other posters wishing to try and see this from BT's side go ahead, it's not actually helpful here as we have spent weeks trying to accept systems don't always work, it's a new service, error happen etc etc, so forgive me if you feel ignored.
I'll post when it is resolved, we are at day 54 currently.