I un authorized charge

There is no such thing as an unauthorized charge. Anything charged to your Apple account was charged by you or by someone who knows your Apple ID and password. If you think your Apple ID has been compromised see—>If you think your Apple ID has been compromised - Apple Support.

If you received an email or a text that says you were charged it is probably a scam. You can see if you were actually charged by reviewing your purchase history—>See your purchase history for the App Store or iTunes Store - Apple Support