Would not do an exchange

I went to Jet in Carlton Centtre today to exchange goods that I bought yesterday afternoon at Maponya. I went to exchange slippers, a pair of shoes and a set of bras. When I got to the door the security guards refused to write a slip for the exchange for the bras and when I went to the cashier I informed her that I wanted to make an exchange for the bras too she said its against the companys policy, I ended up changing the slippers didnt even change the shoes due to being unhappy that they did not want to exchange the bras I bought yesterday afternoon and when I told them how unhappy I was and I could not look for the size of the shoes then I asked for my money they told me they will give me a gift card this was so fustrating because I had my till slip, they still had a tack and the items were still in a good condition Gracia then called the manager who then came to authorise. I am still very angry that the bras that I wanted to exchange were still in a good condition not worn because I only realised that the sizes were wrong when I got home, they still had tacks attached together and I had my slip. The rule that I was told about it was not noted on the back of the slip.