Need account help. Someone is using my credit card to pay for their Microsoft account and I need it stopped

If you cannot locate the charges on your Microsoft account at all, it's possible that your credit card has been compromised. This means unauthorized charges may have been made on someone else's Microsoft account using your credit card. In such a scenario, you should contact your credit card company to open a dispute case. Microsoft is unable to directly investigate issues related to someone else's account if you contact their Billing Support directly. However, once a dispute case is initiated by your credit card company, Microsoft can then respond specifically to those claims through the dispute process with the credit card company. This is the appropriate channel to resolve such issues, as it ensures proper verification and handling of the unauthorized charges.

I'm sorry you're going through this. Microsoft doesn't know and can't see who's tapping on the keyboard. And it's not Microsoft's responsibility to ascertain whether someone entering valid payment information is entitled to use that payment information. Discover can stop the charges by cancelling your card account and replacing it with a new card account. That's what MasterCard did for me. In addition, my MasterCard has zero liability for fraudulent charges as long as I report them as soon as possible. I hope Discover offers you the same benefit.