The petition, with a citation attached, signed by the Chair or one of the other members of the Commission, or its clerk, shall require the petitionee to appear at a certain time and place within not less than 10 days after the date of such citation. The citation, with the petition, shall be served on the petitionee like a summons, not less than six days before the date he or she is required to appear. At the required time and place, the Commission shall hear the parties and their witnesses and such other evidence as they may offer, and determine the facts and thereupon make such order and decree as the law and justice require, which order shall be final unless appealed from. The Commission may adjourn such hearing from time to time and to another place in the county, and may adjourn it elsewhere if the parties consent. (Amended 1959, No. 329 (Adj. Sess.), § 39(b), eff. March 1, 1961; 1961, No. 180, § 7.)