If you see a charge on your account that is greater than your latest iTunes in-app purchase, don’t worry. Most likely, iTunes has applied a combined charge to your account.
Please be advised that when you make several payments, iTunes usually applies a combined/group charge for all of your recent purchases.
You can double-check your purchase history in Settings in your iPhone, iPod Touch or iPad device and locate which application specifically applied the charge.
Follow these steps:
Go to Settings > [your name] > iTunes & App Store.
Tap your Apple ID, then tap View Apple ID. You might be asked to authenticate your Apple ID.
Scroll to Purchase History and tap it.
Tap on the > to the right of the total billed charge to see invoice details, including the billing date and order ID.