Discovery refuses to pay in full

For the past 2 weeks I have been trying to get a procedure pre-authorized for which Discovery wants to charge a substantial upfront co-payment fee. They will only waive the co-payment fee if the procedure is done in a doctor's rooms and not in a day clinic or hospital. According to them the co-payment is only to cover theatre fees. Subsequently Discovery provided me with a list of doctors who are prepared to do the procedure in their rooms however when phoning these doctors in my area they all insist that the procedure can only be done in a hospital because of the discomfort and the potential problems the procedure can cause when done out of hospital. My frustration is that for the past 2 weeks I have had to battle to get this resolved and Discovery simply refuses to fully pay for the procedure. I pay them along with my normal savings account for a fully covered in hospital plan which should give me full cover for this event. I have spent quite a lot of time on the phone which has already additionally cost me more to resolve. Discovery, please get your house in order and get clarity about why the doctors insist doing these procedures in a hospital.