No payment to claim

Hiving visited the doctor the doctor, I paid cash and submitted the claim to the medical aid a month ago. only to realise that the medical aid decided to pay the doctor again for the claim that I submitted evidence that the invoice was settled in cash. Over the moth I have been trying to correct the error with no joy from either the Dr account rooms or discovery, I have been trying to get refund. reference for the call to discovery ***, ***, ***. Most frustrating is the agents are not prepared to call back hence made to hold ]] the calls for long periods and still no resolution. Also no further updates to why they are not paying until I make another call. In all the conversations I had to start explaining everything. What ever the medical aid requires is not supposed to come from me but the service provider. I furnished all information that proved I made the payment cash. It is not fair for me to double pay the service provider