SIM Locked - No resolution - beyond 48 hour requirement

I bought a iPhone 12Pro (paid in full) when I switched to Xfinity last year. I had assumed (incorrectly, it seems) that since I paid for the phone upfront and had no contract, that my phone wouldn’t be locked to a carrier.

I’ve chosen to try out another carrier and I had already ported my number over, but when I went to insert their SIM card, I was given the SIM Incompatible error; alerting me that my SIM was locked by the carrier. That was 4 days ago.  I immediately called Xfinity support (on a Saturday) and they said they would put the request for unlock in and it would take 48 hours (and yes, I asked if that was 48 business or standard…he assured me it was standard).

On Monday (about 40 hours later), I got an email saying the phone has been unlocked. I checked and it still showed SIM LOCKED. I tried the SIM card and same error.  I’ve now spoken to 7 different mobile reps on the phone and have gone into a store twice. No one seems to know how to tackle this and every person I speak to on the phone keeps moving the goalpost (oh, it’s ANOTHER 48 hours after the email, etc). Additionally, no one seems to be able to explain how Xfinity is going to unlock a phone no longer on their network (or anyone's network, for that matter).  The person I spoke to last evening seemed confident that he had fixed the issue and told me that it would be resolved in "a few business hours" and that he'd call me after a few hours to verify.  That was approximately 18 hours ago and the problem is neither fixed, nor did I get a call back.

This is dumb. I don’t have service and Xfinity seems hellbent on keeping me at arms length from the people who have the technical know-how to resolve this (they’ll put me on hold after I ask a question, then come back 5 minutes later with an answer - as if they’re playing the telephone game).  I've already filed one FCC complaint and seem to be destined to file a new one every day.

Please, for the love of all that is holy…help…me…