[Q] Samsung Galaxy Light SGH-T399n unlock possible? topic

Hello all, I have a Galaxy Light SGH-T399n that was never activated I don't think. I called MetroPCS and they said they could not get me an unlock code. I was able to put TWRP and a rom on it, but I guess that has nothing to do with actually unlocking the carrier? Is there a way to go about this? I have done many google searches and keep ending up at pay services.

Thanks!