(1) If a complaint within the purview of these rules is not satisfactorily adjusted after a period of thirty (30) days following the written notice thereof to the division superintendent by an authorized member of a legislative committee representing employees of a company to which these rules and regulations apply; or, in the absence of any legislative committee representative, some other properly authorized representative; the Montana public service commission, upon proper petition and hearing, may issue an order directing that conditions complained of be corrected. When a hearing on such petition and complaint is ordered held by such commission, due and proper notice shall be given to all interested parties, and the complaining and petitioning party will have the burden of establishing the fact of which it complains.