You can follow along here.
https://support.microsoft.com/en-us/help/12412/microsoft-account-how-to-close-account
Also try using the Open Get Help app here, do the microsoft bot dance and you'll eventually get to chat with microsoft account support.
https://support.microsoft.com/en-us/contactus/
--please don't forget to Accept as answer if the reply is helpful--
Regards, Dave Patrick ....
Microsoft Certified Professional
Microsoft MVP [Windows Server] Datacenter Management
Disclaimer: This posting is provided "AS IS" with no warranties or guarantees, and confers no rights.