The commission may at any time, after notice, and after opportunity to be heard as provided in Section 77-3-47, rescind or amend any order or decision made by it. Any order rescinding or amending a prior order or decision shall, when served upon the utility affected and after notice thereof is given to the other parties to the proceedings, have the same effect as original orders or decisions. However, no such order shall affect the legality or validity of any acts done by said utility before service upon it of the notice of such change.
Miss. Code § 77-3-61