So here is a interesting one... I upgraded to the iphone 5S last friday... Got the phone today.. and I called att as this was a swap.. I know you can just change the sim but I didn't want to deactivate the other line... well no upgrade shows up in the att system.. all my lines upgrades are still available.. The guy was just like I don't know what to say you didn't accept a new two year agreement and that can't be done over the phone as it is only done when you purchase the phone.. and now here is the kicker.. apple also said i had not used a upgrade.. i am at a lose..