“Earned and redeemed enough for a $20 prepaid card (37,500 points), which went fine but just took time and effort. Then I spent several months earning 92,500 points to get $50, and was told that there was a system error that overpaid me for my activities, and a "prorated amount" was being returned to me... less than 17,000. Repeated requests for more details or other contact have been met with just a generic reply.”