so? just send them proof you're not.

Did you change your birthdate on Twitter? They've been doing that to people who's changed their birthdate (kind of dumb, but ye)

They also do that to account that were originally created when the user was under 13. So if you created your account when you were 12, even if you’re older now, Twitter has been known to do this.

If this happens they usually restore your account and delete any tweets made prior to your 13th birthday.