Need help with medical billing codes

I have been working with my doctor for over a year to get him to submit a correct statement to my insurance company (UHC). So far, he has submitted 10 statements, all of which were denied due to incorrect billing codes or an incorrect allocation of units per treatment episode. I would like to find someone who could work with me to identify correct billing codes and unit allocation, which I would then ask my doctor to resubmit to UHC. Thank you.