I fail to see how following the information (and applying) in BT's Residential Code of Practice would lead to termination and a poor credit rating. If it went this far then I would be contacting BT Executive Complaints; who I have the greatest respect for and always found to be very helpful and responsive (cue the Mods deleting my reference to the existence of said function)
Just to briefly update. We now have a broadband service as of a few days ago following the long awaited upgrading of our exchange.
This forum seemed to have produced the only helpful and useful response from bt.
Genuine thanks to Neil who not only e-mailed me but actually called us (twice) to discuss the issue and check broadband was actually working. It was a pleasant surprise to be put in touch with someone who took ownership for the issue. If only all my contact with bt had been of this quality!