Unrealistic exchange policy during festive season

I purchased 4 Packard Bell Tablets, 3 for our kids and 1 for my mother on the 31st of November 2024 as Christmas gifts. As soon as we bought them, we wrapped them in Christmas wrapping paper. When my kids opened them on Christmas morning, they discovered two of the tablets did not work, as they did not switch on at all. When returning to Makro to exchange the tablets we were advised that because it was later then their 14-day exchange policy, they could not refund or replace the tablets but would have to send them to the supplier for repairs, The suppliers only open on the 6th of January 2025. This means my kids will not be able to enjoy their Christmas gifts over the festive period. I cannot believe they advised me that we should have opened and tested them before wrapping them. They were sealed in their packaging. Were we supposed to give opened 2nd hand tablets as gifts? How can this be their policy for any electronic items purchased as gifts?