I have been charged for something i did not authorize

Please refund

We can't, as we are fellow users we don't have the ability.

Have you looked at the purchase histories of all iTunes accounts linked to the card, that will tell you what the charges are (assuming that they are actual charges on your iTunes account) : See your purchase history in the iTunes Store - Apple Support ? Do they show ?

If not, and if they aren't : About payment card authorisation holds in the iTunes Store - Apple Support, you should be talking to the card issuer.

If they do show, and if neither you nor anyone you've given access to the account did them (i.e. if the account has been hacked, in which case I assume you've already changed the account's password), you should talk to iTunes Support : http://www.apple.com/support/itunes/ww