Help with a tricky situation

Hi, I hope this is the right place to be posting. It’s kind of insurance adjacent. So my girlfriend recently went to the ER for some abnormal feeling in her heart. Turns out she had some other stuff that they needed to keep her there for 4 more days. She had an awesome doctor and a great experience overall. The doctor even gave her his card but unfortunately she forgot it at the hospital.

Well today she found out that her insurance denied her claim. She hasn’t had a primary care Dr in a few years due to moving around a bit; so she tried calling the hospital to get in contact with her ER doctor to help with the appeal. The lady at the hospital who picked up the phone refused to get her in contact with the doctor despite explaining the whole situation. I’m sure it’s some type of standard hospital policy but the lady was really rude about it which seemed unnecessary.

I guess my question is: What recourse, if any, is there for this? This is in Minnesota if that’s pertinent.