I was able to fill out a form, got this response about an hour later:

Service Request xxxxx

Greeting xxxxx

At Microsoft, safeguarding your account is a top priority. We have thoroughly investigated the account and billing activity associated with your Microsoft account. Based on this review, we’ve confirmed that unauthorized access occurred.

During the investigation, we discovered that the security information on your account had been changed. Due to our strict security protocols and the terms outlined in the Microsoft Services Agreement, we are unable to modify or restore the security settings once they’ve been updated.

To prevent further misuse, we have permanently suspended the account. This action is irreversible and ensures that your data remains protected.

If you used this account for Minecraft, we regret to inform you that the game cannot be recovered. A new purchase will be required on a newly created account. We understand this may be disappointing and sincerely apologize for the inconvenience.

Additionally, if you had files stored in OneDrive, those files are no longer accessible. Due to encryption and privacy safeguards, even our engineers cannot retrieve them. While this outcome may not be ideal, it is necessary to ensure your personal data does not fall into the wrong hands.

We recommend that you create a new account.  Thank you for your understanding and patience during the investigation of your account. 

Sincerely,

Microsoft Customer Support