Momentum not willing to rectify wrongful claim after authorization was done prior to claim submitted

I decided to make use of my mayor medical aid benefits with Momentum health. I got the necessary per-authorization for a GP visit as well as papsmear performed by the GP. I booked my appointment, gave printouts of the authorizations to the doctor. The doctor processed everything correct and the correct codes were used for the GP visit. However the specimen is tested by a third party whom decided to use totally different codes as to what was given. The full amount for the test was now taken from my savings account on my medical aid instead of the medical aid paying for this. I have sent emails and get automated emails in return. Eventually I got feedback from a consultant, Chanelle Naidoo stating the 3rd party used a different code and they won't amend from their side or question the pathologist even though there was pre-authorization for this test in advance. I have done everything that was expected from me as a Momentum client and a patient, yet I am being told directly that the claim already went through on a different code for my account, no assistance given, no explanation as to why my authorization was ignore nothing. I am in the process of getting Momentum life Insurance but this is making me rethink it completely. Why offer these benefits if you are unwilling to stick to what is promised to the client and refuse to sort it out. By far the worst ever, thinking you are doing the right think, doing everything by the book and then being **** to and no one willing to rectify this as the claim went to Momentum not to me and this is a 3rd party, I am not able to rectify this.