credit card charges

Note A hold will be applied to your credit card in the amount of $400.00 (plus any applicable taxes). This hold is not a charge against your credit card. However, it may affect your credit card balance until we remove the hold. Your credit card will not
be charged and the hold will be removed,

Most pre-paid credit cards do not allow recurring charges, and that is a requirement for an XBox Live subscription (promotional or regular) to be charged to a credit card.

I thought that a charge from a credit card is the same as a bank account? There's no way it would charge your bank account directly without a credit card on file.

You can contact your credit card company and explain the situation to them and they will initiate a credit card number change to prevent unauthorized charges to your account. Alternatively if you have set up that you need to authorize a purchase that incurs
a charge before they are completed then you shouldn't need to worry. Just monitor your credit card and if an unauthorized charge occurs then you can contact your credit card company to have it reversed. Most credit card companies allow you dispute a charge
that was not made by you within a certain timeframe. So as long as you monitor it you won't be held responsible if a charge does indeed occur.

I agree. That was my issue --- fraudulent charges on the credit card. I contacted the credit card company, and they addressed the problem. Unauthorized charges and a compromised card number may be what happened in your situation, too.