Momentum not paying claims

I was hospitalised last year 2023 for a life threatening condition, authorization was granted for the procedure. A few months later I get notified by the hospital that there is an outstanding amount of about R17 000 that I need to settle as the medical aid did not pay. I followed up with Momentum, they told me to get a motivation letter from the hospital as to why they should pay those items. I did all of that, the hospital sent the motivation letter to Momentum on 3 April 2024 but till today Momentum has not rep****. A follow up was made but still no response. My hospital account is now being handed over. I am very disappointed with Momentum, I have been experiencing claim issues with them as there was another which I sent to my gap cover but gap cover advised that they should have paid. With the help and follow up from my gap cover provider they ended up paying it.