Charged instead of refund

I bought shoes and clothes from Ackermans lifestyle they were the wrong size. I went to return them at Ackermans Mall@Reds. I got to change some clothes but the shoes they did not have on the shelf.i didn't realize the cashier when changing the clothes charged me again for the shoes instead of refunding me. I only realised this when I got home that I was charged for the shoes and the clothes I exchanged. I was supposed to get a refund for the shoes. I went back and was told they would go through the slip and call me the following day. I have not received a call and cannot keep driving there it's costly.