Oh, I'd go for the Apple Store. They actually know. Someone at the AT&T I'd think was hit or miss.
Especially if the AT&T is between you and the Apple Store, seems a better bet to try Apple first and then if they tell you it's a provider issue (who knows, right?) you can hit them on the way back.
You can look up the store online and make a reservation/appointment for the genius bar. Sometimes they're busy and if the random employee can't fix it (it was a random employee on the floor who fixed mine but if it is more serious...) they'd tell you to come back for the genius bar, so reserve an appt. online before you go in, that way you know you'll get taken care of.
Especially if the AT&T is between you and the Apple Store, seems a better bet to try Apple first and then if they tell you it's a provider issue (who knows, right?) you can hit them on the way back.
You can look up the store online and make a reservation/appointment for the genius bar. Sometimes they're busy and if the random employee can't fix it (it was a random employee on the floor who fixed mine but if it is more serious...) they'd tell you to come back for the genius bar, so reserve an appt. online before you go in, that way you know you'll get taken care of.






i am def. a new user 
