Getting ****med

Went to Medi Clinic Tzaneen as a cash paying patient but now I keep on getting messages that my medical aid didn’t pay for certain services which I already had advised that I will use cash of which I did pay. Now I’m left with a payment I wasn’t advised about when I got discharged and I did pay the money I was told to pay. Did call them a month ago and they said they will investigate and revert and I’ve been waiting