Miscellaneous topics that do not fit into specific categories.
If the charges match nothing in your subscriptions or order history, your card number is most likely being used on someone else's Microsoft account. You can't see that account, and neither can support show it to you. Your bank dispute is the fix for that, and killing the card was the right move.
Quick checks:
- Compare the charges against ALL your Microsoft accounts and family members' accounts, especially kids' Xbox purchases: https://support.microsoft.com/en-us/account-billing/how-to-investigate-a-billing-charge-from-microsoft-398c5328-364c-d5e4-ea8f-f5ad60562a93
- Remove the old card at account.microsoft.com > Payment options, and check account.live.com/activity for strange sign-ins. If you find any, change password and enable two-step verification.
- To reach a human: https://support.microsoft.com/contactus > sign in > type "unauthorized charges" > scroll past the articles > Contact Support > choose chat. Chat gets a live agent, no hang-ups.
If the charges came from an account that isn't yours, the agent will confirm the bank dispute is the resolution. That's the correct answer, not a brush-off.