Selling an old blender as new

On the03/08/2024 me mad my daughter went to the Upington Kalahari Mall branch of Checkers. There we purchased a blender and I paid with my credit card for it. Just to get home and discover that it's a used blender that doesn't even work. So now my question is how come an old product gets put on the shelves and than it's been presented and sold as a new item. This is not the first time I'm experiencing such the last time it was at Shoprite. And from that experience I've learned that when it comes to customer service and trying to exchange a product like that you've to jump through hoops like your the one that made the mistake in the first place. Why is it so difficult just to get service you pay for cause I'm not expecting to find an old product on the shelves when I go to buy from any store. I've been struggling with flu that's why I haven't gone back to the store as yet also now I've to waste my time and money to go and exchange this blender and all this due to a mistake made by Checkers.