3week wait for stock ends in refused refund

Shopping at christmas times is no fun so this year when i purchased a sneaker a size to small, i decided to call the store about a bigger size instead of going back into the mayhem for nothing. Called the high que store two days after purchase and was told they did not have anything in the size I wanted. So I asked if i could be informed as soon as they do get stock in within the next 2weeks as my refund lasted 30 days. Few days before xmas i was called and told that no store had the size im looking for. Unfortunately for my son, he had no sneakers xmas but i still intend on doing the exchange. At week 3 i called all edcon store close to me and was told there was no size 14 only sizes 9 down in every brand. At this point i decided it futile and went to get the refund before the time period lapsed. At the store the manager told me I could not return sneaker because it was not in the original form as when they took it off the shelf. My son did not fit the shoe on in the shop but at homeand we do not have carpets so the sole was not perfect white but a bit dusty. He literally put it on, walked around the house for 3min then said its hurting. Now because he wore it for more than a few seconds its non-refundable, which is utter **** in my books. I believe the manager looked at my return date, being after xmas and all, and just decided that Im pulling a fast one. Extremely ****ed by this service recieved especially because I was in contact with the store for the entire period I had the shoe. The store and the staff answering the phone was aware of my return, then just to be told by a manager that I cannot get an exchange just super ****ed me off. I feel ****** of my time, patience and money. Disgusting!!!!