Well, that was a waste of time. I just spent 25 minutes waiting then explaining the problem to someone, who then proceeded to tell me that I can't activate my BT ID until after my installation date.
Surely that's not the case? The guy on the phone when I placed my order explicitly said I could use the WiFi spots before the install using my BT ID, and they have immediately sent me the email to set it up. A big company like BT can't get something like that wrong, is it?
Any other ideas?