(1) When complaint has been made to the commission concerning any rate, fare, toll, rental or charge for any product or commodity furnished or service performed by any public utility, and the commission has found, after investigation, that the public utility has charged an amount for such product, commodity or service in excess of the schedules, rates and tariffs on file with the commission, or has charged an unjust, unreasonable or discriminatory amount against the complainant, the commission may order that the public utility make due reparation to the complainant therefor, with interest from the date of collection.
(2) If the public utility does not comply with the order for the payment of reparation within the time specified in such order, suit may be instituted in any court of competent jurisdiction to recover the same. All complaints concerning unjust, unreasonable or discriminatory charges shall be filed with the commission within one year, and those concerning charges in excess of the schedules, rates and tariffs on file with the commission shall be filed with the commission within two years, from the time such charge was made, and all complaints for the enforcement of any order of the commission shall be filed in court within one year from the date of such order. The remedy in this section provided shall be cumulative and in addition to any other remedy or remedies under this title in case of failure of a public utility to obey an order or decision of the commission.