If an attacker successfully changed the email address and the password for your account, and you did not setup multifactor authentication, I'm very sorry to tell you: your account is gone. There is nothing that Microsoft can do to change that.
You can show Microsoft any number of detailed screenshots and linked third party accounts - so can your attacker, because they own your account and have access to all the information in your account. They are now you, insofar as your account is concerned.
No one at Microsoft has met you, to be able to distinguish you from anyone else. For cloud accounts like a Microsoft account or a Google account or an Apple account, etc., whoever has the right username and password owns the account.
Even if you were somehow able to retrieve your account, are you sure you'd want it? Your attacker could have sent out millions of spam messages in your name, or used the payment card in your account (if any) to make fraudulent purchases, or who knows what else, using the information that is stored in your account.
You must take steps to protect your identity. While you are spending time going in circles with AI bots and filling out forms, your attacker has free reign over your account. Protect yourself!