i have a 2 year contract right now that is currently complete and i'm just paying month to month. according to at&t, i'm eligible to upgrade using next OR another 2 year contract. can i upgrade using next at the apple store? or is it only 2 year contracts. they have the 128gb 6 pluses in stock and i'd rather not shell out $499 especially since if i can get it on next, it'll be easier to expense the total wireless bill monthly. make my employer pay for my new phone.