Being forced to folk out a co- payment

I recently went for Gastroscopy in hospital on the 14th of January and Momentum required me to pay an amount of 1000.00 as this is regarded as a specialised procedure. The results came back indicated that I have a Gastro-Oesophagus Reflex disease (GERD) due to Hiatus Hernia. The doctor has recommended surgery on the 16th of Feb. To my amazement, Momentum Health wants me to pay another co-payment of R1000.00 even though the Gastroscopy form part of the Surgery. Upon further enquiries with the call Centre, I was told that I can avoid the co-payment if I told the doctor to perform an open surgery instead of the proposed LAPAROSCOPIC ANTI-REFLUX surgery which the Doctor to drill 5 small incisions and work with the aid of Cameras hence the use of gastroscopy. open surgery is more risky and will require more days in hospital while the other one has less stay in hospital and quick recovery time. I am very disappointed with Momentum as they want to penalise me as a member for choosing a less risky option which will in turn save them more money on my hospital bills. I am now even contemplating of looking for another medical aid as my plea seems to be falling on death ears .