Refund

I paid rcs by mistake using capitec app. They said I must send proof of payment I did but no response. I was paying my standard bank credit card using capitec app . I went to standard bank they said they don't know where the money is I must go to capitec. I went to capitec they traced the money and they said it went to Rcs we did call rcs they said I must send proof of payment I did of which they don't respond the consultant said they only communicate with emails.