N17 Hospital has no clue

I had a procedure done in November. I got authorization from my medical aid and they assured me there is no co-payment. Net care and the N17 hospital have been hounding me for money I supposedly owe them. My medical aid says they booked only 1 of the 2 procedures and that has a co-payment. (the 2 procedures must be done together to be covered fully) The medical aid did write a letter to them explaining the error. I complained to the Netcare complaints line and they still don't understand and have not fixed the account. They are threatening me with legal action and still hounding me on the phone.

How can one trust the N17 hospital with your life when they can't even get the bill right!