You own your number. You should be able to port it and take it to whatever carrier you choose. That's T-Mobile's device until you pay it. Although, I believe since it's unlocked you can use it where ever you choose. You just won't be allowed back on their network and they'll attack your credit for the device costs. There may be flags placed on the serial number of the device but I'm not positive how that works.
As far as what you owe, you were probably approved for $0 down device financing and the monthly payments occurred so long as you had an active account and service plan with them. The moment you cancelled meant the device charges were due immediately.
10-11-2016 08:18 AM