Can I give my phone back in order to get a new one with T-Mobile?

Ok so l upgrades to a used iPhone 6s Plus 64 gb from a iPhone 5s that l had for 4 years. The phone l have Now is 576 dollars but l see iPhone 7's for the same price brand new l just got this phone in July is there anyway l can trade in my phone in order to get a new one without paying this one off?

No get a vaJJ one instead

Speak to T-mobile, but don't be surprised if they treat you like a nutter or just laugh at you!