Citigroup Inc is entitled to recoup about $500 million of its own money that it accidentally wired Revlon Inc lenders three years early, a U.S. appeals court said on Thursday. Reversing a lower court ruling, the 2nd U.S. Circuit Court of Appeals in Manhattan said it was improper to give the lenders a "huge windfall" by letting them keep Citigroup's money, and that they had been on notice the wiring was a mistake.