Medical aid claim

Kindly assist .On the April 18th 2019 I went to Dis-chem South gate mall to get a prescription for my child that amounted to R518.23 . On that day the lady by the name Nomvula that was helping me struggled with the code ,the system wasn't accepting the prescription code . but eventually she said it went through. she gave me the medication and I left. The following month I received a statement from bank med stating that I owe them R 518.23 on my medical aid . Than I logged a query with bank med regrading the issue of which I spoke to a lady by the name Ingrid Smith of which sh explained to me that apparently Dis-chem claimed the money , bank med paid after getting the money they reversed the claim all they needed to do was to resubmit the claim and up until this day she never got back to me since she promise to resolved the matter . I also went to dis-chem customer service at South gate my self , they told me it has been fixed . since last year I have been receiving the statements/demand form bank med to pay the R 518.23 of which I am not going to pay since I never received any cash form dis-chem and they took the money form my medical aid and they failed to resubmit the claim since last yer may 2019 till date as they were requested to do so.