Hi. I'm Brian and I'll try to help.
You cannot delete a Microsoft account without being able to log in and Microsoft won't do it for you.
You may submit the automated recovery form at most twice per day, but you can take up to a year. It is imperative that you keep your recovery and verification data up to date.
If no one accesses your account for two years, Microsoft permanently disables it, but it sounds like it has been stolen from you. If you had any credit cards connected to the account, it's time to get those cards reissued.