Just recently I have been reading a great deal about people having issues with BT and broadband connections, mainly connected with their MAC codes.
It seems to me that just recently there has been lots of complaints (not just with BT) and that the whole industry is letting service slip. The problem is that no matter how much you shout you are still at the big companies mercy.
I just hope everything finally works out for you and that your broadband is in and working as promised in the 7-10days time scale indicated.