XFINITY MOBILE WON'T UNLOCK YOUR PHONE

I paid off a phone that they refuse to let us take it another carrier. The phone is paid off and was going to be my 11yr old daughter's first ever phone, but Xfinity is refusing to unlock it. I called customer service days ago to ensure that the phone would be unlocked when the sim card from Mint Mobile arrived. They assured me it would be. That was a lie as I've spent hours today on the phone and they keep making excuses ("there's an error, "call back later", etc.) . I'm paying for a plan through Mint Mobile that I can't use because Xfinity won't release our property, and my daughter is stuck without a phone until Xfinity pulls it's head out of it's own you-know-what. Judging by the countless other reviews dating back years, this is an extremely common tactic they use. This company is absolutely deplorable, and I would not recommend Xfinity to anyone. *They'll leave a response telling me to contact them via chat, but they'll still make excuses why they ,magically can't unlock my phone...