Tried that. The site wouldn’t work. When going through the Apple site it couldn’t find my ATT account. Tried it over several days. I’m guessing it’s on the ATT side of that though.
It found my AT&T account with no problem.
Did you try flushing your cache on your device before doing it again?
If so or you did it on a different device, then I guess you should ask AT&T? I’ve been with AT&T for a long time (over 15 years). Who knows?
When I bought my iPhone 4s at an Apple Store two years ago, the Apple techs had all kinds of problems with ATT to get my account set up. It took 3 hours and an intervention by the Apple central tech control office for ATT to get their act together.