AT&T stores don't have iPhones in stock. they only take orders which take 10-21 days just to ship. mine took 14 days and in that time i went to the apple store and bought one.
now i just gotta go to AT&T and cancel the order. you should check iphone availabilty on apples website thought at 9pm the day before you go. it lets you know what types of iphones they are getting the next day in their shipment.
i went the next morning and got a reserved ticket in the morning, went to work, and went back to the store and bought it at like 3 in the afternoon.
it was easy to do and suggest buying it at the apple store.