Wrong Account Reported / "Accidentally Reported You"
The way the scam works is a user will tell you they reported your account and show you a screenshot of an email from Discord. The email will list the username of an "employee" that you should contact. If you contacted the "employee", they will tell you to change your email address to one they will provide. When you change your email to it, they will have effectively stolen your account and will hold it for ransom. This scam has been running for a while and exists in other platforms as well.
If you encounter users like these and notice this pattern, just block, and report the user contacting you. Read the Reporting Abusive Behavior to Discord article for more info on how to report users.