Physician refusal to correct coding error in record

I found a coding error in my own medical record. Evidently the physician put 493.21 (chronic obstructive lung disease with status asthmaticus) in rather than 493.00 (extrinsic asthma). There is a huge difference in those two codes and I do not have the one that appears in the records!!
After nearly 20 phone calls the clinic now tells me that I have to have a pulmonary function test to prove the coding error wrong and convince the physician to correct the records. This is of course additional testing and I will have a copay for a test I don't need.

I am going in circles with a diagnosis that is very incorrect and I am getting nowhere with this issue. Is this a compliance issue? Where do I go from here? Help!!

Physician refusal to correct coding error in record