WASHINGTON — Retailers have applauded two Supreme Court actions in cases regarding credit cards. Late last month the court overturned a ruling barring retailers from imposing a surcharge on credit card use, sending the case back to a lower court. Two days earlier, the Supreme Court justices declined to hear a bid to resurrect a $7.25 billion antitrust settlement of price fixing charges against Mastercard Inc. and Visa Inc. The National Retail Federation (NRF) welcomed the court's refusal to reinstate the class-action lawsuit settlement, which would have blocked merchants from accusing Visa and Mastercard of fixing credit card swipe fees. "If this settlement had been approved, the structure of fees that drive up the prices of everything consumers buy would have been cemented into place forever," said NRF senior vice president and general counsel Mallory Duncan.