It shall be the duty of every contract carrier by motor vehicle to file with the commission, publish, and keep open for public inspection, in the form and manner prescribed by the commission, schedules, or in the discretion of the commission, copies of contracts containing the minimum charges of such carrier for the transportation of passengers in intrastate commerce, and any rule, regulation, or practice affecting such charges and the value of the service thereunder. No such contract carrier, unless otherwise provided by this chapter, shall engage in the transportation of passengers in intrastate commerce unless the minimum charges for such transportation by the carrier have been published, filed and posted in accordance with the provisions of this chapter.

No reduction shall be made in any such charge, either directly or by means of any change in any rule, regulation or practice affecting such charge or the value of service thereunder, except after thirty (30) days’ notice of the proposed change filed in the aforesaid form and manner. However, the commission may, in its discretion and for good cause shown, allow such change upon less notice, or modify the requirements of this section with respect to posting and filing of such schedules or copies of contracts, either in particular instances, or by general order applicable to special or peculiar circumstances or conditions. Such notice shall plainly state the change proposed to be made and the time when such change will take effect.

No such carrier shall demand, charge or collect a less compensation for such transportation than the charges filed in accordance with this section, as affected by any rule, regulation or practice so filed, or as may be prescribed by the commission from time to time, and it shall be unlawful for any such carrier, by the furnishing of special services, facilities, or privileges, or by any other device whatsoever, to charge, accept or receive less than the minimum charges so filed or prescribed. Any such carrier or carriers or any class or group thereof, may apply to the commission for relief from the provisions of this section, and the commission may, after hearing, grant the relief to such extent and for such time, and in such manner as in its judgment is consistent with the public interest and the policy declared in Section 77-7-3.