BT made a complete hash of my install too. I moved into a new build house a few months ago. Fortunately the developers had already installed a BT line as they had used it as a site office, so I assumed that the activation process would be easy. How wrong I was.
Firstly BT refused to acknowledge the existence of the phone lines - despite me providing them with the DDI numbers - and quoted a 60-day lead time. After two weeks of ultimately pointless phones calls to their engineering department there was no other option but to wait for the 60 days.
BT arranged to send a engineer on install day but predictably they didn't turn up or even attempt to call. When I finally got to speak to someone I was told that they had determined a visit wasn't required and could do all the work from the exchange. However - the phone still wasn't working. This was, I was told, due to some work in the exchange and I would get a phone call later.
24 hours later, no service, and no call-back I called again to be told there was a major fault in my local street cabinet affecting all of my neighbours. Strange, I commented, since I'd just been next door to use their broadband connection.
My gripes were now three fold: no service, an engineer no-show, and being outright lied to.
Service, of sorts, was finally delivered three days later - with broadband a massive 768Kbps with CRC errors and a further week of arguments to get a half decent service.
My compensation offer for all the phone calls, inconvenience, etc? £10. An absolute disgrace.