Billing

I went to buy medication on the 13/05/2018 at Dis-chem Dainfern square. I paid cash for my medication and to my suprise on the 15/05/2018 i received an email from Discovery paying a claim that Dischem made for the same medication. i contacted them and spoke to Graham who said what i'm telling him can never happen. i sent him the email from Discovery and my bank statement confirming the 2 transaction and he has not bothered replying. Someone sort this out.