Bad customer service of all time

I bought sneakers at studio 88 in thohoyandou unfortunately it was a small size for my son, then went back to thavhani store and decided to exchange the sneaker with a 2pair of push ins,both 2pair costs R650 and I had to be given a change of R250, the staff ganged up on me and refused to give me the change telling I should get it where I bought the sneaker, I was so disappointed in the service as I am a customer. I still have the pair because they refused to assist me