Purchases I did not make on my credit card

DO NOT click on any links if you received an email 'notifying' you of this charge. Look at your iTunes billing history as explained here: See your purchase history in the App Store or iTunes Store - Apple Support

If it's not there, then you didn't purchase it. Report the email or other notification to Apple as explained here: Phishing & Other Suspicious Emails

If it did get billed to you, then there's two things you need to do:

1. Contact Apple to discuss the charge. The first article listed below is an explanatory link, and the second is a form:

Get help with an item purchased from the App Store, iTunes Store, or iBooks Store - Apple Support

iTunes Store - Contact Us - Apple Support

2. Secure your Apple ID to make sure that nobody else was using it: If you think your Apple ID has been compromised - Apple Support

You need to follow the steps that are provided in the links that I sent you, particularly this link: If you see 'itunes.com/bill' or an unfamiliar charge on your bank, credit card, or debit statement - Apple Support

Did you follow all of those steps? Do you have any specific questions about the process?

The article you were just on describes how to deal with this issue in more depth: If you see 'itunes.com/bill' or an unfamiliar charge on your bank, credit card, or debit statement - Apple Support

Go to this link for official support: contact Apple Support

At this point, just go to this link to contact support: contact Apple Support

Ok, slow down.... Did you receive this charge notification in an email? If so, it may be a fake.

And... Was the purchase in your purchase history on iTunes?