Candy Crush keeps charging from their store

I have a relative to who plays Candy Crush on their iphone and for some reason almost every 2-3 months, candy crush will make unauthorized purchases from their store without their permission.

I tried changing the password because I figured the Apple account may have been compromised, but it's still doing it. I have a password prompt turned before anyone can make any purchases and I have no subscriptions running that I'm aware of so I don't understand why this keeps happening.