Cricket Locked MY phone.

I have been a Cricket customer for over a year...

I bought a new iphone XS at Best Buy with no sim card and no cell service contract, was told it will work with all providers.  I removed the sim card (Cricket) from my old device, installed in my new phone and powered up, it worked immediately.  About a month later I tried to switch service to Verizon who told me phone was compatible.  Tried their sim card and doesn't work because Cricket locked my phone.  Yes, MY PHONE, that I paid for in full. I have not been able to get Cricket to unlock my phone.  I had to pay for another months service Or lose my number and still have a locked phone. 

What gives a "bring your device, pay as you go" company the right to lock my phone?  I have spoken with Cricket support every day to get this resolved to no avail. They keep promising to call me back, still waiting.

Verizon charged me for sim card and first months service before they would try the sim card. They told me when I asked for refund that this was a non-refundable purchase.

Cricket needs to get their act together.  I have a $1,000.00 door stop that is too thin to even work as a door stop. I am being held for ransom at Cricket because I don't want to lose my number.  Of course if I go past the cut off date, I will lose the ability to access Cricket support.

What am I supposed to do at this point?  NOT A HAPPY CUSTOMER!