1. See Wisconsin Statutes 196.01

   (1)   

      (a)    No public utility and no agent, as defined in s. 196.66 (3) (a), or officer of a public utility, directly or indirectly, may charge, demand, collect or receive from any person more or less compensation for any service rendered or to be rendered by it in or affecting or relating to the production, transmission, delivery or furnishing of heat, light, water, or power or for any service in connection therewith, than that prescribed in the published schedules or tariffs then in force, or established under this chapter, or than it charges, demands, collects or receives from any other person for a like contemporaneous service.

      (b)    A public utility or an agent that violates par. (a) shall be deemed guilty of unjust discrimination and shall forfeit not less than $100 nor more than $5,000 for each offense. An officer who violates par. (a) shall be fined not less than $50 nor more than $2,500 for each offense.

   (3)   If a public utility gives an unreasonable preference or advantage to any person or subjects any person to any unreasonable prejudice or disadvantage, the public utility shall be deemed guilty of unjust discrimination. A public utility violating this subsection shall forfeit not less than $50 nor more than $5,000 for each offense.