This is a strange one, I moved into my flat on the 11th and I had my BT line activated on the 23rd. There was a problem with the wiring in the flat (the person that lived there before me had cut the cable inside the BT socket) - I logged a fault on the 23rd when I realised the problem and they had an engineer out to me by 3pm the next day. I'm guessing they may only be backed up certain areas?
Fault engineers are a completely different allocation than connection engineers, not the same timescales etc