Shoppers across the region flocked to area malls today to score major discounts on the third-busiest shopping day of 2011. Stores opened early in anticipation of massive crowds looking for even larger deals. Many businesses offered cutbacks of up to 70 percent for returns, exchanges and new purchases. "These things are normally two times the price," says Gill Mach, of White Plains. Retailers are advising customers to bring their receipts, and to know how much their gift cards are worth.Thousands of last-minute shoppers hit WC, HV malls