Nothing contained in Articles 1, 3 and 5 of this chapter shall authorize the Commission to declare any rate, toll, charge or fare contained in any contract voluntarily entered into prior to March 24, 1922 for a term of years by and between any public utility and any person or corporation, whether public, private or municipal, for the sale and purchase of gas, or other commodity, the subject of such contract, to be unreasonable and noncompensatory without the consent of both parties to such contract.
S.C. Code § 58-5-50