I've seen a lot of people saying that want to return their phone of the other model (6+ for a 6 and vice versa) and it got me thinking to about how that would work with Next. With Next you're technically still "under contract" until the total cost of the phone is paid off, or you can upgrade after a certain period by trading your phone in. (ie. 18 months on the Next 24 plan). What happens if you're say a year into your contract and think "You know what, I really want that 6s +)? How does that work? do you still get a trade in credit and pay the difference, or do you pay it off and then sell it on your own? Sorry if this was asked already, I didnt see it and am just curious.