Worst experience no refunds no exchange they still have my Shoes

I had the worst experience ever,I even left my Shoes at the shop because they didn't want to exchange for me because I lost my slip and I was only looking for the bigger size...I tried to tell them am coming from polokwane coming to Sandton to buy and now I came just for exchange they told me I must wait for the manger until she's done with the meeting .I bought on 16 and return them on the 29 November