Poor and unfair service!!!

When I went to their South Africa website I saw the training shoes I like, price is in rands then I went ahead and ordered my size which is size 6,5 and when I got them it was a size 4. When I contact them they said sizes are US sizes and they don't do exchanges. I'm SAD because I spent almost R5k for this. What will I do with them 😞 I wonder what the retail association say about this kind of service, if they take back they sell them again but me what will I do with a wrong size. As I speak they are just sitting in my closet!