I want my Money back

I visited Netcare The Bay on the 11th of Dec 2018, paid R1200.00 to the hospital then I was soon Admitted, got authorisation from the medical aid. I was then discharged on the 13th, Medical Aid then informed me that they had paid all the money to the Hospital and i was supposed to get a refund for the cash payment i made at the hospital (R1200.00). I visited the hospital and they gave me a number to call ( Their Head Office), i have tried calling numerous times but no answer, the medical aid claims department also tried to assist, but they also came back to me saying their was no answer. Went back to the hospital again this week and they promised to send the invoice to Head Office, and they would copy me, that was not done because i have not yet received any communication to show that they are communicating with Head Office. All they kept mentioning was that this process could take 2-3 months to get the money back. i can not understand was is that the process can take up to 3 months to get a response while the Medical aid had paid them within a few days. This is unacceptable