The CFPB just nicked American Express. The following article describes penalties to be paid back to consumers for violations dating back to 2003 by American Express
https://www.businessweek.com/ap/2012-10-01/amex-paying-112m-in-late-fee-settlements
As the article describes, American Express was found to have violated federal laws by using false statement to get customers to settle old debts. They were found to have falsely told customers that if they agreed to settlements to partially pay off their debts, the remaining balance would be forgiven. As a result of these false statements American Express will be sending out $112.5 million dollars to about 250,000 cardholders affected by this illegal behavior. If you are one of those entitled to a refund, you will be given notice in the mail soon.