Blacklisted by mistake

I bought my iphone 13 in October directly from AT&T's website.  Yesterday it was blacklisted.  The AT&T rep that I spent an hour with on the phone said it was reported stolen and there was nothing he could do.  I am literally still paying AT&T for the phone on my bill every month.  It has not left my possession, so I assume that someone accidentally reported or keyed in the wrong IMEI number.  When I asked the rep if I could speak to the fraud dept, he said I couldn't because I didn't make the report.  And that there was no one I could escalate to.  That seems really wrong.  I have had this account in my name for over 15 years.  It feels like someone has stolen my phone from me without it ever leaving my possession.  I get the whole idea behind being able to brick stolen phones, but surely there is some way to correct mistakes?