You need to be a customer of Tmobile USA and meet the requirements in the link below.

https://www.t-mobile.com/responsibility/consumer-info/policies/sim-unlock-policy

TMobile says can't unlock my phone it's not paid for I joined TMobile on a promo that the phone was free with plan for 175.00 1 time payment and I signed with TMobile WiFi and haven't seen 75.00 credit to any of my bills

The phone is being paid off by bill credits so it can't be unlocked until the phone is paid off, you can pay the balance of the bill credits then unlock the phone if you meet the usage requirements.

Thank you I wished they would have explained all this in English 

That's how they lock you in to 2 years because of the bill credits.