Payment calculation errors

I have submitted a claim whereby I had to pay upfront tor services renderer by the Dr. in hospital. When I requested for the claim to be processed and paid out, Bestmed made an error when calculating the total invoice cost. When I provided the medical aid statement to the gap cover company they indicated that they require "a detailed medical aid statement showing the processed account. Please do not forward a claims processed transaction history", Bestmed failed to provide the updated detailed medical aid statement. I made numerous calls and send mails trying to resolve this. Today I yet again received the same statement that the Gap cover people rejected. I am trying to get this information for more than 2 months already!!

I am truly upset with Bestmed and poor service they render