37-3-102. Only prescribed rates to be charged. No public utility shall directly or indirectly, by any device whatsoever, or in anywise, charge, demand, collect or receive from any person a greater or less or different compensation for any service rendered or to be rendered by such public utility than that prescribed in the schedules of such public utility then filed and published in the manner provided in this act, nor shall any person receive or accept any service from a public utility for a compensation greater, less or in any way different from that prescribed in such schedules.
Wyoming Legal Code