Many of us know from experience that BT's methods can be hard to fathom and sometimes exasperating, but just waiting for things to happen won't make it better.
Did you challenge the siting of the master socket? Have you sought advice about the connection problems? Didn't you realise that stopping a Direct Debit was likely cause a payment to be missed? Have you done anything to prevent repetitive late payments? Have you considered alternative payment methods? Have you asked BT to confirm your account number? Have you done anything to ensure you see a bill?
Best of luck with your new provider, but you might need to do your bit to get things to run smoothly.
These sorts of postings always confuse me ! If you get paid once per month, and BT take their direct debit once per month, why the bank charges ? It shouldn't make any difference whether the DD goes out on the 1st of the month or on the 30th.
What IS annoying is when payments are taken late one month and then early the next, so that (sometimes) a payment due towards the end of the month is not taken until a day or two into the next month, and then a second payment goes out at the end of that same month. But even then it shouldn't make any difference - in theory - if it is budgeted for.
I thoroughly agree though that saying "sorry you can't change your payment date" when you are paying by DD is very poor customer service, especially when you consider that those (like me) who get a monthy bill and pay manually get given a couple of weeks to make the payment !