Child account - defunct e-mail and forgotten password

I've forgotten the E-mail that I used to create the account, and when I normally try to log in to the account on my Xbox 360 it says that it needs the E-mail and the password.

For whatever reason it would not allow me to post this in the orginal post

Many years ago when I created gamertag I used my work e-mail address as my login. I have long since forgotten the password for my account, and I have moved through three companies. I have attempted to change it both through the menus on my xbox and
through the windows live help center. When attempting to either reset or add an additional e-mail address to the account it must first be verified through an e-mail sent to a many year old, now defunct work e-mail address. I seem to be stuck in an endless
loop. Any solutions would be much appriciated, even a number for a call center... I'm at my wits end, hoping for help.

First, get the email account from your Xbox by following these steps
support.xbox.com/.../forgot-microsoft-account (Find your Parent Microsoft Account)

Copy down the email address and visit
account.live.com/.../reset, click "I forgot my password" and "Reset your password". Enter the email address from before and solve the word puzzle. Click "I can't use any of these options."

You will need to fill out a questionnaire designed to prove your identity. That should give you access to your account.

If this does not solve your problem, contact Microsoft Support at
support.xbox.com/contact-us

support.xbox.com/contact-us and select your issue. You'll be able to request a call back from support (bypassing long hold times), verify the account, and the support agent will be able to
cancel it for you.

I've also been having this issue.

My parent account's e-mail is defunct, so it's kind of impossible to have an account that doesn't exist grant me permission to do something.