S.C. Code Ann. § 58-27-830: Utility shall not charge rates different from those in schedule.

No electrical utility shall directly or indirectly, by any device whatsoever or in any way, charge, demand, collect or receive from any person, corporation or municipality a greater or less compensation for any electric current or service rendered or supplied or to be rendered or supplied by such electrical utility than that prescribed in the schedules of such electrical utility applicable thereto then on file in the manner provided in this chapter, nor shall any person, corporation or municipality receive or accept any service, electric current, product or commodity from an electric utility for a compensation greater or less than that prescribed in such schedules.