Defective shoes refund

Hi, I bought a pair of defective all star boot size six from Xkids store in Eastgate Mall on the 21-10-2019. I went back the following to exchange for size 5. I asked the store manager about price difference, because this time I was taking a low cut. The manager advises that she was working it out. Only to realise that she wanted to use the size seven shoe to avoid price difference. The staff advised that white all star is the same price as boot (six hundred). The price on the size five shoe was shown as five hundred and fifty. Before I opted to buy from xkids the previous day, I compared prices, all stores were pricing their shoes per size (my personal observation). To cut the long story short, I left the store with a red pair. I am demanding a refund of fifty rands. The CPA is overriding your policy that says no cash refund. You cannot force me to take a gift card because of your price inefficiencies. The manager was supposed to explain to me why she was using a size seven shoe while there was clearly a size five on the system. According to the store manager, there is nothing I can do to change that. If that is true, then I am willing to exhaust all available measures. I asked for regional manager's contacts to no avail. This is by far the most unproffessional service. Refer to Section 48(1)(c) of the CPA.