Impossible to get money back

My son had an op and the doctor advised me that there were extra charges that the medical aid did not cover so i paid the charges only to find out from Discovery that they also paid the amounts. Now i am unable to get my money back from the doctor. Discovery say they can only tell the doctor to give it back and the doctor is not. Please i need some help with getting my money back, there must be something more Discovery can help me with. This is their contracted doctor and he is *****ing your clients money and you are doing nothing? Please, or else my only other solution will be to go to the ombudsman and the press