Fed up with Fedhealth

After obtaining the hospital authorization for an operation we received an account for the Anesthetic. Medical aid paid less than a third of the bill. Tried to query with Fedhealth and just received a message saying doctor is not contracted to Fedhealth. How are we supposed to know who is contracted to the medical aid scheme when we did our part of obtaining an authorization number? There is just no cover or customer's best interest at Fedhealth. Trying to get answers is a futile exercise with consultants reading from screens