(a) Whenever the Commission, after a hearing had after reasonable notice upon its own motion or upon complaint of anyone directly interested, finds that the existing rates in effect and collected by any public utility are unjust, unreasonable, insufficient or discriminatory, or in violation of any provision of law, the Commission shall determine the just, reasonable, and sufficient and nondiscriminatory rates to be thereafter observed and in force, and shall fix the same by order.
(b) All municipalities in the State are deemed to be directly interested in the rates and service of public utilities operating in such municipalities, and may institute or participate in proceedings before the Commission involving such rates or service. Any municipality may institute proceedings before the Commission to eliminate unfair and unreasonable discrimination in rates or service by any public utility between such complainant or its inhabitants and any other municipality or its inhabitants, and the Commission shall, upon complaint, after hearing afforded to the public utility affected and to all municipalities affected, have authority to remove such discrimination.
(c) If any refund is made to a distributing company operating as a public utility in North Carolina of charges paid to the company from which the distributing company obtains the energy, service or commodity distributed, the Commission may, in cases where the charges have been included in rates paid by the customers of the distributing company, require said distributing company to distribute said refund plus interest among the distributing company's customers in a manner prescribed by the Commission. The amount of said interest shall be determined pursuant to G.S. 62-130(e). (Ex. Sess. 1913, c. 20, s. 7; C.S., s. 1083; 1933, c. 134, s. 8; c. 307, s. 8; 1937, c. 401; 1941, c. 97; 1963, c. 1165, s. 1; 1981, c. 460, s. 1.)