Bad customer service ever

Good morning. I bought shoes for my son at rage a week ago and only realized today when I tried to fit him that there too small. I then requested my sis to go change them now at the Diepkloof square branch,to my surprised they refused to change not refund them and gave us an explanation that they are not in good condition while he didn't even worn them. I'm just disgusted and disappointed with this kind of service we get. I promise not to recommend anyone to buy at this shop even again. I now see why most people do complain regarding this shop. I need an urgent assistance in this matter.