Problems with medical billing errors drive me crazy. Not our bills, but the medical bills of relatives and friends. They complain to me all the time. I start by telling them--you are complaining to the wrong person. Then I explain to them what to do about it--pick up the phone and call whoever is billing you.
I learned a long time ago, you can negotiate down the price of any medical bill.
Don't be afraid to pick up the phone and say--I refuse to pay that amount. Experience tells me that you can get a 20 percent reduction just by opening your mouth--by being proactive. By the way, being proactive does not mean being mean. Start by remembering this, the person on the other end of the phone is just like you or me--they are doing a job. So treat them with respect. You can get more with sugar then you can with vinegar.
If you run into a brick wall, try the above then use my favorite word--Supervisor.