Complaints against motor carriers; statement of charges; satisfaction or investigation of complaint

Any person, firm, association of persons, corporation, municipality, or county, complaining of anything done or omitted to be done by any motor carrier subject to this chapter, in contravention of the provisions thereof, or any duty owing by it under the provisions of this chapter, may present to the commission a petition which shall succinctly state all the facts. Whereupon, if there shall be any reasonable ground to investigate such complaint, a statement of the charges thus made shall be forwarded by the commission to such motor carrier, which shall be called upon to satisfy such complaint or to answer the same in writing within a reasonable time to be specified by the commission. If such motor carrier of property by motor vehicle within the time specified shall make reparations for the injury alleged to have been done or to correct the practice complained of and obey the law and discharge its duties in the premises, then it shall be relieved of liability to the complainant for the particular violation of law or duty complained of. If such motor carrier shall not satisfy the complaint within the time specified it shall be the duty of the commission to investigate the same in such manner and by such means as it shall deem proper.