Q: Unauthorized purchases

Which restrictions have you set, both in-app purchases and 'require password' ? And you've checked your purchase history to see what the purchases are e.g. are they auto-renewing subscriptions, or did you have any pre-orders that were due ?

You can view your account's purchase history via your computer's iTunes : log into your account on your computer's iTunes via the Store > View Account menu option, you should then see a Purchase History section with a 'see all' link to the right of it. Click on that and you should then see a list of your purchases.