Managing personal Outlook.com account settings, security, and privacy
Hi ,
I'm afraid that account recovery is an automated process. Please use the Sign-in Helper tool first:
https://support.microsoft.com/en-us/accounts-billing/manage/i-can-t-sign-in-to-my-microsoft-account
If it does not help, fill out the recovery form with accurate information, such as name, birth date, old phone number, Skype/Xbox information, or subscriptions. Be noted that it takes time until you receive a response.
I wish I had better news, but if you enabled 2 factor authentication or if the hacker changed the associated email address, unfortunately, the form does not work and the account will not be recovered.