Well that's good to hear.
So I should go to an AT&T Corp store as opposed to an Apple store?
Also, did you need the phone for the line you are taking the upgrade from with you at the AT&T store?
Because I'd be taking the upgrade from my grandpa, but he's in Florida and I'm in New York.
While I prefer buying from the Apple store when possible, I'd recommend the ATT store for this as they can do whatever they have to in terms of using upgrades from 1 line but activating for another.
You won't need the other person's phone [as long as you're the account holder/able to make changes].