Shop does not want to give money back!!

My mother purchased a bag of R680.00 at this shop in January month. She went to take it back because she found another suitable bag at some other store and they said they can only give her a credit note. However there is nothing in the store that she wants or likes at this moment. Bearing in mind nowhere on the slip it states that they don't do refunds, not even a note saying this in the shop. I phoned the owner Bothma and he said he is not going to argue with me no matter what the consumer act says, they don't give money back coz if they did then how would businesses make money? Everybody will then just buy stuff and come back after a while saying they don't want it. He was actually very sarcastic!! The bag is still in its original condition with tags on and she still has the slip for the bag so I would just like him to give her money back.. Getting a credit note is like money lying around of which you could've used for something else.