Phone company doesn't want to replace iphone 11 although I had insurance on it? Claims it was on the "Sim". Can't I fight this?

I bought a new iphone in September with ATT and I got insurance on it the same time. Well my boyfriend did, were all on the same family plan. He switched his sim card and gave me the new phone, we basically swapped phones. But again we bought insurance with it and the clerk told us it would be fine. Here comes 2 days before Christmas and a coworker stole my phone. I thought I had insurance on the phone since we've been paying for it for almost 3 months! and they tell us the insurance isn't on that phone anymore its on the sim card. So our old phone now has insurance and not the phone that got stolen. I find it so ridiculous! And I don't know what to do they said its nothing they can do about it. Even though I have a police report, and proof. They could literally see the same day I bought the phone was the same day I bought insurance.