Went to have a simple surgery done got charged for...

Went to have a simple surgery done got charged for two operating rooms. They won't listen when I tell them that they fraudulent billed both me and my insurance provider. This comes after they demanded we pay the full price prior to the procedure being done. Even before they sent the bill to my insurance company. Then when you call patient advocacy they fail to follow up with you even though they claim they will. Takes a week and even then they still have to take longer to review everything.