You've checked the purchase history on your account and you didn't have any pre-orders that have been released nor have any auto-renewing subscriptions ? If you 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 purchasesIf neither you nor anybody who
If you didn't make the purchases, and nobody else has access to your account nor devices and may have done so, then you can try contacting iTunes support via this page : http://www.apple.com/support/itunes/contact/- click on Contact iTunes Store Support on the right-hand side of the page, then Purchases, Billing & Redemption