The whole freaking thing is a giant scam. It's set up and designed to screw the patient and maximize income for the doctors and providers. It's impossible to understand or navigate the myriad billing intricacies unless you're a medical billing pro and it's the result of decades of refusal to do anything about it. Legislatures and government are sold to the highest bidder and that's the providers and insurance companies rather than the patients.
Good luck and just be thankful it wasn't something expensive like cancer or heart surgery.
Everybody hates the lawyers, but a couple hundred mass tort suits against providers for deceptive billing practices and malfeasance in their estimates of cost might be good if they wouldn't just jack up prices further to cover it.