Very Disappointed

So I bought a game for my kids (for the upcoming school holidays) and it loads onto the console before you can play and it stopped at 70% and I assumed it was internet related we started over a few times and then I realised it must be the disc at this point it's 4 days that has passed so I remembered they had another copy there and asked if I could swap the game out for the children as I know they had a 24 to 48 hour money back guarantee on it. So I figured I'm not asking for the money it and the games were basically the same price with a R10 difference which I would gladly pay if needed the manager of the branch a gentleman told me "how must he now sells that broken copy" to which I rep**** but it was fine to sell it to me. I've bought there many times before and this was very disappointing, You have one less customer and I will share my experience with everyone I know as it is the truth and I wouldn't want this happening to someone else