Retail store added the wrong phone to my plan

A corporate ATT stor added the wrong phone to my plan in June 2022 and we have been getting charged for it. I got an S22 they added a Samsung ultra. I never had a Samsung ultra. I did like it but they didn't have any in store and with my Note 9 originally I wanted to downsize so I opted for the S22 really for the size. Anyway we have been calling since now the retailer say they can't help us! They credit us and create a case but never fix it. Now I need to file a claim with my insurance on my S22 due to screen issues but I cant since our account says I have an Ultra. How can I get this ressolved. I am thinking about getting a lawyer because this is just wrong.