If a complaint is not dismissed under Sec. 604.28, but is deficient as to one or more of the requirements set forth in Sec. 604.27, the Office of the Chief Counsel may dismiss the complaint within 20 days after receiving it. Dismissal shall be without prejudice and the complainant may re-file after amendment to correct the deficiency. The Chief Counsel's dismissal shall include the reasons for the dismissal without prejudice.