S.D. Codified Laws § 49-13-13
If, after a hearing pursuant to this chapter, it appears to the satisfaction of the commission that anything has been done or omitted to be done in violation of the provisions of laws of this state, or that any individual or joint rate or charge demanded, charged, collected, or received by any telecommunications company or motor carrier subject to the provisions of this title, or that any individual or joint classifications, regulations, or practices of a telecommunications company or motor carrier are unjust, unreasonable, unjustly discriminatory, unduly preferential, prejudicial, or otherwise in violation of the laws of this state, or that any injury or damage has been sustained by any person, the commission may determine and prescribe the just and reasonable charge, to be observed as the maximum to be charged. The commission shall also determine what classification, regulation, or practice is just, fair, and reasonable to be thereafter followed, and to make an order that such telecommunications company or motor carrier shall cease and desist from the violations to the extent that the commission finds them to exist. The telecommunications company or motor carrier may not thereafter publish, demand, collect, or receive any rate or charge for in excess of the maximum rate or charge prescribed and they shall adopt the classification and conform and abide by the regulations or practices prescribed by the commission.
SDCL 49-13-13