Wells Fargo acknowledged Friday that for six years about 570,000 of its customers were charged for auto insurance they didn't need, potentially driving some to default on their loan and have their cars repossessed. The San Francisco bank said it would start refunding about $80 million, or about $140 each, to customers next month. The revelation quickly sparked a backlash from lawmakers still angry after Wells Fargo admitted last year that thousands of its employees had created millions of fake credit card and bank accounts for customers without their knowledge. "No wonder so many hard-working Americans believe the system is rigged against them in Wall Street's favor," Sen. Sherrod Brown, the ranking Democrat on the Banking Committee, said in a statement. Sen. Elizabeth Warren ... renewed her call for the Federal Reserve to force Wells Fargo's board of directors to resign. "There are surely deep ... problems at a bank when it opens millions of fake customer accounts and charges nearly a million customers for a financial product they don't need," Warren said in a statement. "The Wells Fargo Board is ultimately responsible for that failure." Wells Fargo said the most recent scandal is centered on its auto lending business. Customers' loan contracts require them to maintain auto insurance and allow the bank to buy it for them if there is no evidence that the customers have a policy, the bank said. But ... customers were being charged for auto insurance premiums even though they already had another policy.