Hi, thanks for reporting this. Are you still able to sign in to your Outlook account or did someone change the password?
The first step is to secure your Microsoft account by resetting the password from the official Microsoft Account Recovery page and then removing any unknown recovery info or recent sign-ins from your security settings on the Microsoft account website. Turn on two-step verification to protect access.
Once you are back in control, you can request to close the Outlook account from the same account management page. Also contact Amazon Support right away to report the unauthorized purchases and remove the Outlook address from your Amazon profile.