i recently bought a used i phone 6s when i went vacation in greece really cheap but when i tried my sim the phone was locked..i tried returning it and the shop owner told me they accept no returns i felt like calling the police on him but i didn't want to cause a scene and stuff.. after some research i found an online service that told me that the phone was locked in t mobile and it wasn't reported stolen and the previous owner had already payed for everything.. so i tried contacting here for an unlock and it says i should contact some agent that can help me via "message us: but when i try it says i need to sign in.. when i try to create a new account it says that i need a t mobile phone number to register.. i don't have one so how can i contact the agent? thanks in advance for replies!
You can contact T-Mobile on Twitter or Facebook or you can give T-Mobile a phone call.
but basically you can't unlock the phone without being a customer for a certain period of time. Truthfully the previous owner should've had the phone unlocked before selling it. I don't have the direct link available however you can Google search for T-Mobile's unlock policy.
Manage your T-Mobile account