Request declined by Discovery

I have been going back and forth to get covered for a procedure for the past 4 months and no success. I had my Dr complete the necessary form as well as sent the Dr's motivation letter for a small procedure to be covered. It has been declined by Discovery. I tried calling various Discovery health numbers and I am told the number does not exist. I have been with Discovery for 8+ years and have hardly ever used my medical aid. I am considering switching.