Grandson downloaded a game without my permission
can I get my money back?
can I get my money back?
Maybe. You'll need to talk with iTunes Billing.
https://www.apple.com/emea/support/itunes/account/
But FYI: Usually, all purchases are final.
http://www.apple.com/legal/internet-services/itunes/us/terms.html
You should also set restriction on downloading apps to OFF.
Settings > General > Restrictions > Installing Apps: OFF
Grandson downloaded a game without my permission