Un outhorized charged to my AMEX
I need a phone number for billing department at ITone , to asked them about this charged amount on my AMEX?
The iTunes Store has no phone support.
As to your question, first, log into your iTunes Store account and see if the purchases are reflected in the Purchase History. If they are and you're sure you or someone you know didn't make the purchase, immediately change the password to your iTunes Store account, making sure it's not something easily guessed or looked up. Then go here:
http://www.apple.com/support/itunes/contact/
and follow the instructions to report the issue to the iTunes Store.
If the charges are not reflected in the Purchase History, then it's most likely a fraudulent charge to your credit card directly rather than an unauthorized purchase through your iTunes Store account and it will be up to your bank to handle.
Regards.