Managing personal Outlook.com account settings, security, and privacy
Hello, thank you for contacting us.
It appears that the hackers removed your email address (alias) from your Microsoft account and replaced it with their own. When this happens, it is as if the email address will be permanently deleted. Additionally, if it is a Microsoft Personal domain email address, it cannot be associated with another Microsoft account or recreated.
To help prevent this type of situation, Microsoft always recommends that the account users to protect their accounts with a strong Microsoft account password and enable two-factor authentication for enhanced security. This way, even if someone knows your password, they would still need a second verification method, such as a verification code or an authenticator app, to sign in.
In the current scenario, since the account has been deleted, you cannot use the account recovery form to recover it because the email address has been removed from the servers.
In this situation, your only option is to contact the Xbox Account Recovery team, which handles compromised accounts even when the email address has been changed. Try to provide all the required details accurately and submit the form.