Horrible Manager

I have had the worst experience with the manager at the Sandton Mall Pick and Pay Clothing Store. I had purchased 4 pairs of shoes for my kids. Yesterday I returned 2 of the shoes as they didn't fit. The cashier kept my slip and didn't return it back to me. Today I returned the other 2 pairs of shoes as the shoes were not fitting and it seems to be hurting the kids. The manager Thali refused to refund or credit me as he says that I didn't have the till slip. I tried explaining to him countless times that they took the slip yesterday and he refused to help me exchange the shoes! I mean it had the prices, the barcodes and everything on it! The worst PNP Clothing store manager I have come across