EQUALITY OF RATES AND SERVICES.

(a) A public utility may not directly or indirectly charge, demand, or receive from a person a greater or lesser compensation for a service provided or to be provided by the utility than the compensation prescribed by the applicable tariff filed under Section 52.251. (b) A person may not knowingly receive or accept a service from a public utility for a compensation greater or less than the compensation prescribed by the tariff. (c) This title does not prevent a cooperative corporation from returning to its members net earnings resulting from its operations in proportion to the members' purchases from or through the corporation.