Complaint to Netcare

Good day I would like to know if you can help me with a continous problem i having concerning my medical aid. My son was admitted to Netcare Bay hospital last year November and stayed there for almost a week. The medical aid has covered half of the payment and is still waiting for paperwork from Dr Thandeka Ngetu's office to send so that they can complete the full payment. There is a outstanding amount of R26000 that they are holding back because of this paperwork. I have continuously been to that office every week to find out that it still has not been sent threw. Today I was verbally insulted by 1 of her staff who continued to scream at me saying that we are not the only people waiting. My point is it does not take you 3 months to send 1 paper through. Medical aid has also informed that if the paperwork is late they will not cover the bills. So how am I suppose to afford this bill when the blame is not on my side. Please advise me on what to do. Thank u