Kan. Stat. § 66-154a
No common carrier shall charge, demand or receive from any person, company or corporation an unreasonable, unfair, unjust or unjustly discriminatory or unduly preferential rate or charge for the transportation of property, or for hauling or storing of freight, or for use of its cars, or for any service afforded by it in the transaction of its business as a common carrier; and upon complaint in writing made to the corporation commission that an unfair, unjust, unreasonable or unjustly discriminatory or unduly preferential rate or charge has been exacted, such commission shall investigate such complaint, and if sustained, shall make a certificate under its seal setting forth what is, and what would have been, a reasonable and just rate or charge for the service rendered, which shall be prima facie evidence of the matter therein stated.
K.S.A. 66-154a