I upgraded from IPHONE3 to IPHONE4 using my online upgrade option. I received a defective IPHONE4 and was told by tech support that I could take the phone to an ATT STORE for replacement. The store sent me to a corporate owned store. Still no replacement. They told me that ATT sells the phones but does not do exchange or replacements. I had to go to the IPHONE Store to get a new phone. This was after 2 1/2 hours of driving around Orlando and two calls to the tech centers. I had to make an appointment with APPLE and drive the next day to the Apple Store an hour away. Apple couldn't have been more helpful and I now have a working IPHONE.