Billing

if you get some random mail saying you are billed then read

Identify legitimate emails from the App Store or iTunes Store - Apple Support

if you are really billed then if it was me then I would read

Request a refund for apps or content you've bought from Apple – Apple Support (UK)

and or reach out to Apple Support

One of the charges will be for something else.

View your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Support

Every charge to your account will be specified in the purchase history.

We can't tell you. You will have to ask Apple. This is a user to user forum not an Apple service area.

Click on Get Support - also at the top of this page.

Under View your products click on Choose a Product >

Then select Show All

Billing & Subscriptions

and then follow the prompts.