So I'm currently on AT&T's Next plan with a 32GB Iphone 5S. I have about $350 in installments to pay if I wanted to do their early Pay-To-Upgrade option. I've read that some users were able to Trade in their iphone 5S (while on the NEXT plan) and get $300 in trade-in credit, which they then used to pay off the rest of their installments (or at least the portion that the credit covers, and then paying the remainder). I tried to to do this at my local AT&T store and they said it wasn't possible because it the Next plan is excluded from AT&T's trade-in/ buyback program. Has anyone done this and succeeded in receiving that trade-in credit, while on the NEXT plan? Am I missing something here? Or have I just been misled?