POOR SERVICE WITH QUERIES

i have been getting letters from doctors saying that i owe them money yet the procedures and service dates were done in hospital and these were all covered for as part of the medical aid cover, now im told that i will be blacklisted for non payment,,, whats the use of having a medical aid that claims that the cover inhospital treatments that were authorized by them before hand!! i have queried this issue on numerous occasions but no one can give me positive feedback or any feedback at all. very disappointing that they put the clients in bad light for no reason. especially Fedhealth that is so big and usually carries a good name. i hope someone capable can do something efficient