Fuck Caliber Collision

At the end of 2023, I got in a minor accident. I went to Caliber to get it fixed in early 2024. I got the alert saying it was done, paid a crazy fee for what was essentially a damaged bumper and went home. Today, I get a call at 10am, they said I owed them $500. They said the old GM made an agreement with me that I would come back and pay it to get my car back. I don’t ever remember making this agreement. Like I said, i paid a fee and the guy said it was fine. The new GM said I had to pay it or they’d send a creditor after me. Over the course of an entire year I didn’t get a call, email, carrier pigeon, nothing saying I was delinquent on a payment.

Be honest with me, did I fuck up? How could this possibly happen? Any advice?