Railroad companies shall adjust all freight charges promptly when shipments are delivered, and apply only the legal, published rates and classifications in effect at time shipment moved from point of origin.
Actual weights must be observed in settling charges, unless otherwise, provided for in classification.
If, after settlement is made, an overcharge appears, the railroad company collecting such overcharges shall make proper refund to shipper or consignee when demand is made and said overcharge is shown.
S.C. Code Regs. § 103-37