Imperial Health review: Billing errors - poor response from escalation

I was billed for the copay that was paid in the office. I compared my EOB to the bill and the discounted amount on the EOB was reduced on the bill by exactly the copay amount and showing that I owed the copay amount. I have called multiple times talking with billing then the escalation department providing the EOB in question for the service date. It has been 6 months since the service and I called again today. The issue has not been corrected and is still under review. It is a simple issue but no one seams to be able to read or handle simple math. My Dr will not provide services until the bill is resolved. I hope they have good lawyers.