Decling of procedure due to dr not registered

Mr dr recommend a certain procedure for an operation that needs to be done. The code 1807 was used and they declined it. They also sent a sms saying that dr is out contracted and I must pay the difference above med aid tariffs. I clarified that and dr said he will charge medical aid tariffs. He also mailed a motivation as to the pros and coins of the 2 different procedures. I also wrote a letter asking them for their favorable approval because I have a mentally disabled daughter of 25 who needs my assistance in her sanitation and hygiene. The procedure he recommend is only 1 night i hosp whereas the one they approved are 3 days. They declined it again so I phoned them yesterday as I could not understand why they are declining it. Then they said but they are declining the procedure because of the fact the doctor is not listed. On my question which doctor are listed in our area there was none. The nearest one in Durbanville about 500 km from us. My concern is I am paying the same as the other members who are staying where there list of doctors are so why must we get second best because if you read through the motivation his option are the better one. Please help. Thanking you Amanda