Microsoft can't help you. Nobody else can help you. Only you.
Don't waste time talking to AI bots and filling out forms. It's much too late for that.
There is nothing that Microsoft can do when a Microsoft account has been stolen. And it wouldn't matter even if they could do something, because the thief has by now made a copy of all the information about you that they need.
FIRST: Close all your credit cards, debit cards, call your bank(s) about your bank accounts. Freeze your credit reports. Inform all other financial institutions with which you are doing business.
Abandon your Microsoft account. You'll never get it back and it's no good to you anyway.
Erase your hard drive and reinstall your software. Backup your personal files before you start.
Get a brand new Microsoft account and warn all your contacts not to open mail from your old address.
Change all your passwords while you still can.
Be constantly vigilant for signs that your identity has been stolen and take action immediately to shut it down.
Are you in the United States or subject to its law?
Federal Trade Commission Identity Theft.gov
What can I do if I am a victim of identity theft? from the US Consumer Financial Protection Bureau
Identity Theft Guide for Individuals from the IRS
Report Identity Theft from the Federal Trade Commission
Plenty more information is available on the internet. The above are a solid start. Artificial intelligence can help you. If you need a prompt, try this:
My Microsoft account has been stolen by someone unknown to me. The thief has already started to impersonate me on the internet and make unauthorized purchases with my payment information. What steps can I take to avoid financial loss, regain access to password-protected accounts, and maintain my good name? Please list your advice in order of importance, with the most important steps appearing first.