The Department of Veterans Affairs has known for more than a year that military service members were being sold a flood of costly and risky mortgages and done little to stop it. The result: Borrowers have been saddled with thousands of dollars in fees, and interest rates have risen for millions of rank-and-file homeowners. Lenders, hunting for business in a slow market, have swarmed into VA mortgages, sometimes selling military homeowners new loans every few months. Some are pushing shor ..