Inconsistent service levels

I took my car for service in March at mercedes Constatia kloof, I overpaid and was promised a refund. They requested a copy of my Id which I submitted and I was informed that they will contact me for a refund. A month went by and no feedback was forthcoming. I sent emails which were ignored by the service advisor. In april I took my car in for repairs, again i overpaid and requested feedback. This time too no feed back was forthcoming from the service advisor. Frustrated I escalated to the dealer principals office. The PA referred me to a manager I don't know why she wouldn't let me speak to the dealer principal. 2 more days went by and the service advisor sent me an email stating that she went through the invoices and that there would be no refund. I then responded and requested that she explain the discrepancy between the amounts I paid and the invoices that were issued to me. To date no feedback gas been received. This is now 3 days later and not a word.<br> <br> I think this dealership undermines African black people. I rather go service my car in another province. I will never take my car to be serviced at that dealership again. Maybe my next car will be a BMW or Audi