U.S. says six airlines issue $622 million in refunds

WASHINGTON, Nov 14 (Reuters) - The U.S. Transportation Department said Monday that six airlines were slapped with $7.25 million in penalties and agreed to issue $622 million in passenger refunds as the agency vows to aggressively enforce consumer protections.The actions helped ensure the carriers paid required refunds "to hundreds of thousands of passengers who had their flights canceled or significantly…