Can I trade in my iPhone 6 for a new iPhone 6?

My iPhone 6 has no scratches or cracks but I feel like it's slowing down on me. IIm in the T-Mobile jump program where I can upgrade my phone anytime, but I just want to trade my phone in for a regular iPhone 6, not 6s. Anyone know if I have to pay a difference?

What did tmobile tell you?

If you feel it is slowing down then try a restore. I doubt T-Mobile would let you do that.