Hi.
This is taken directly from Carrefours own website:
"How do I make a return?
Is there any product from your purchase that you would like to return?
All purchases can be returned at any hypermarket, we can pick them up at home, or if you have purchased from a marketplace (products sold by third parties, see conditions in Marketplace Returns).
Both the product, its packaging and original accessories must be in perfect condition ."
That last sentence, the one mentioning packaging. That is illegal. And im doing everyting i can to make sure the right people find out about it so Carrefour will be heavily fined