Unpayed bills

I am highly dissapointed with the service and outcome that I have received from FedHealth. I had a knee operation done in November 2014. Prior 2 the operation I received approval from the medical aid to do a re construction of my ACL ligament in my knee. Days before I went in for the operation I called distinctly to ask what are the cost involved on my side as I would be unable to pay for this operation cash. The lady I spoke to said that a co payment of R3500 was needed and the rest would b sorted out. I went ahead with the operation and I'm march this year I got a call from the hospital saying I have to pay a balance of R18000. When I called Fedhealth they stated that my entry zone cover did not cover the prosthesis which was done on my knee. Why did nobody inform me about this payment prior to the operation ? In June I got another call from the orthopedics saying that I owe them R2200 for the leg brace. Again why was I not informed about all the cost prior to the operation. I am force to cancel mine and my families medical aid in order to pay for the hospital bills that fed health did not cover. Im highly dissapointed with fedhealths transparency and I'd never refer them to any1