69-12-503. Rates to be reasonable and nondiscriminatory. (1) All rates, fares, charges, classifications, or rules of service for the transportation of property and/or persons upon the public highways of this state must be fair, just, reasonable, and nondiscriminatory. No motor carrier operating under established rates shall make, give, or permit any undue preference or advantage to any particular person, company, corporation, locality, or description of traffic, nor shall such motor carrier subject any particular person, company, corporation, locality, or description of traffic to any prejudice or disadvantage in any respect. Nothing herein provided shall prevent the commission from authorizing different rates or schedules of rates for service between the same places or between different points of origin and/or destination within the same places when such different rates are justified by the differing character of service to be rendered by the carrier to a shipper or consignee.

(2) The commission may, upon its own initiative or upon the complaint of any interested party, investigate any rate, fare, charge, classification, or rule of service contained in the schedule of any motor carrier. If the commission shall find, after such investigation, that any such rate, fare, charge, classification, or rule of service is unfair, unjust, unreasonable, or discriminatory, it shall disallow the same and fix a rate, fare, charge, classification, or rule of service which shall be fair, just, reasonable, and nondiscriminatory and it shall order the affected motor carrier or carriers to conform to such modified schedule. Each motor carrier affected by any complaint or investigation shall first be given notice of the same and an opportunity to be heard before the commission.