cancel apple account funding
How does one reverse a credit card charge that added funds to the "Apple Account"? There are helpful links to redeem the Apple Account funds and to "Add Money", but nothing apparent to undo a mistaken transfer.
Contact iTunes Support for assistance. See the Apple Support articles below for contact information.
Apple Support schedule phone call
If necessary, try Twitter
https://twitter.com/AppleSupport. People have posted it may take an hour or more to get a response.