I've already cancelled one card because of charges showing up for I-tunes on my credit card bill. Now they are showing up again. Have no idea what the charges are for & should not have any as I've never purchased anything on I-Tunes.
iPhone 3G
If the purchase isn't listed in your purchase history then it may not have been taken by your iTunes account and it might be your bank account that has been compromised not your iTunes account.
If you have recently added the payment method, updated the billing information or added a family member, it may also be a holding charge. Holding charges are applied to ensure your payment account is account and are removed after a short period of time.
If you still aren't sure what this charge is for you need to contact your bank immediately.
Charges on my credit card
