Proper service established on complaint

(1) Any person desirous of making a complaint against a public utility provider shall make the complaint in the same manner provided under subsection (1) of section 15 of this Act, and where the Commission hears such complaint, it shall proceed in the manner provided under subsection (2) of that section. 17 (2) The provisions of section 16 of this Act, shall, mutatis mutandis, apply in respect of the burden of proof applicable in showing that the service complained of is fair and reasonable.