I feel bad for the parent, who took responsibility and admitted fault. I don’t see why Twitch can’t undo the transactions, which were clearly fraudulent.
It sucks all around but someone has to end up holding the bag
That's one of the problems. People think you get the same level of protection on a debit card that you do on a credit card, and that's simply not true.
In the US, never use debit cards. Always use a credit card.