Following the filing of a petition, there shall be a period of five business days during which any interested person, other than the appellant, may file comments with the commissioner with proof that a copy of such comments was served upon the appellant. Comments shall be accompanied by a written statement that all factual assertions in the comments are true, and shall be signed and dated by the person making the assertions. Following the comment period, the commissioner shall make a decision in writing disposing of the appeal. The decision shall contain findings of fact and conclusions of law, and shall be served by the commissioner by registered mail upon the appellant and all other person to whom the order being appealed was addressed.