Murphy Oil USA is expected to settle a class action lawsuit over incorrect sales tax assessments, and many customers will benefit.   Murphy Oil has stores in 24 states. The company charged customers too much sales tax on items that were discounted or on sale in 24 states including Florida and Alabama. Anyone who bought a discounted item, but paid the sales tax on the regular price at a Murphy Oil-owned convenience store after January 8th, 2016, can register to receive a coupon.