Try signing into your original account, if your able to access your original account, then I would notify Microsoft of the other person's account that you have access to and just continue to use your own account. This does sometimes happen where your assigned
another gamers account, it's possibly just a glitch. Just report the glitch and enjoy your own account.
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.