Refused a refund and told to go report at headquarters

Yesterday I went to Call it Spring at Menlyn to buy a pair of shoes. I needed a pink pair of shoes to wear with my graduation outfit. I found the last pair in the shop, of which 1 of the shoes was on display, and had been fit by other customers. I asked if was going to be given a discount since I was buying a display item, the manager said no I wasn't going to get it because she didn't have the authority and a lot of other excuses. Anyway I was in a hurry to my graduation, I just paid for the shoes. Before I left the shop I asked about their refund policy because I didn't even have enough time to fit the shoes. The manager told me o had 30 days to return the shoes for a refund. She said but the shoes are nice and they match with your outfit, I then responded that is not enough, they need to be comfortable and I need to feel good in them. To cut the long story short, I put on the shoes when I got to the graduation venue, and walked to the hall in them. But by the time graduation was over, I got to my car walking barefoot with the shoes on my hands. The front strap was absolutely tight, it felt as though blood wasn't flowing to my toes! Today I went back to call it spring Menlyn to return the shoes and tried to explain my predicament, but the same manager refused to give me my refund and said because I have worn the shoes I can't get a refund! She was so rude when I tried to reason with her to try and find a solution to the problem, but she was of no help and instead put on a show inside the shop and told me to go and report at head office! What do I do with shoes that are squeezing the life out of my feet?