Shinamae so lucky you found out before your direct debits bounced, I'm glad the bank alerted you. I'm sorry your grandson didn't understand he was paying with real money - what age are the games for? I used to run the youth club for 8-12 year olds and some of the kids told me their parents allowed them to play the 16+ games which did involve being on line and money. Luckily we didn't have wifi there at the time.
Such a shock for you, I hope you can get it sorted tomorrow.
I've had a shock too, but not serious like yours, but my person is 70 years older than yours! I gave my best friend's partner my old Kindle, I thought he might like to read some of the books I've purchased. I have left my account details on it because if I delete them the books disappear, I explained clearly when I gave it to him it was for reading only - but when I went on tonight to buy a new book for mine, he's put his name on my account! Awkward, I'm going to have to ask him to delete it.
Best of luck tomorrow.