Account Sent to Collections

Hi, my account was suspended and then sent to collections due to non-payment. However, my devices are still carrier locked. I assume I will be paying the credit collections company directly as Xfinity has already sold the debt to them and the agency mailed me my invoice already. I am uncertain what now to do with these devices. The device I have only had $114 left to be completely paid up. I was not even allowed to pay that amount to free the phone. My question is, what do I do now with these phones to have them unlocked? If not both, at least the phone I paid for 98% of.  Any help would be appreciated. I sat inside an Xfinity location after having spoken with two representatives beforehand about the situation. I was in there on the phone on hold for 3-4 hours of my day. Just looking for a real person to speak to who may be able to help me.