Not only must you get a different device, but you'll owe Microsoft an earlyterminationfee that will still bring your total outlay to 70 percent of your service commitment.
That small amount of profit would come after you received your Buy-Back credit in the form of a Best Buy gift card and absorbed the penalty of breaking your two-year phone contract, commonly known as an earlyterminationfee (ETF).
T-Mobile gets some credit for addressing the negative connotations of a legally binding agreement and an earlytermination"fee, " but if you want to keep the phone you obtained at the discounted price, you'll have to keep paying monthly installments until it's paid off.