Training people to reject claims

I did visit a Specialist, as a follow up, twice a year, as allowed by Discovery. They rejected the claim because I did not have a authorization number. They already authorized two visits yearly on the 4 chronic diseases that I have. Firstly they told my wife that the wrong IC10 code have been used, now it's another story. I truly believe this medical aids train/instruct their people to look for reasons not to pay claims.