Specialist approved treatment not paid

To whom it may concern, a week ago I wrote a compliment regarding the way the consultant dealt with my specialist treatment. I am in general very happy with Momentum, but the issue that I currently have is dragging on a bit, and I can't keep phoning in and nothing gets resolved. My Dermatologist procedure was approved for the amount of R 3500 ( procedure ) + R 750 ( the first consult ) , where the procedure was around 3 Nov, till now I have only received R 655.80 back? I don't understand why? Also I needed to get 4 injections post procedure where the doctor mentioned this in the costs on the first motivation letter which cost me R 500! & the consultant want another motivation letter for this, where the Doctor actually refused to write another letter because he has done so. I am not sure why this matter is so difficult. Somebody senior please help.