Hey, In order to unlink in account you must be able to authenticate it (log into it), without being able to authenticate it you wont be able to unlink it. [i]Bungie [b]cannot[/b] unlink an account on your behalf for security reasons.[/i] You will need to work with [url=https://help.steampowered.com/en/]Steam Support[/url] in order to try and recover the account used. Furthermore I would recommend have a look at the [url=https://help.bungie.net/hc/en-us/articles/360048721292-Account-Security-Guide]Account Security Guide[/url] for more information on securing your account in the future.