Confusing situation - medical bills, auto insurance - any reason to be worried?

(originally posted in legaladvice but no replies)

Long story so I’ll summarize best I can.

I was in a car accident where I was not at fault. Went to ER with minor injuries. When I went to the ER, the receptionist mentioned she’d file the visit under “car accident” so didn’t need health insurance info.

Other insurance accepted fault, I signed a release which stated they accepted responsibility of bills on date of accident.

Fast forward, I receive bills, forward them to at-fault insurance company. They pay them. Everything should be done with, but it isnt.

Fast forward some more, somehow my health insurance company filed a claim for the ER visit. Nobody can tell me who filed it, how it got filed, etc. considering I didn’t provide the info at the visit. It was a health plan that I had never used, not even once, so it wasn’t already on file or anything.

So now the hospital adjusts the bill to reflect having “insurance”. My original bills had “uninsured discount” on them. The issue here is the hospital is now sending an adjusted bill for $3,100 instead of the $450 which was already paid to them from the car insurance company.

Then last week, I get a notification through email that the hospital is refunding the $450 payment, with the $3,100 still pending on my account. I can’t get an explanation as to why they refunded it.

To further complicate it, the health plan I had (I have since changed plans) wouldn’t cover anything as it was high deductible. EOB I receive clearly states plan contribution is $0. BUT they are denying the claim anyway because I didn’t use my car insurance medical benefit to go towards the hospital bill. I didn’t use my auto insurance at all because I had no reason to.