While I thought I was booking a room at the Hyatt Place on the National Mall in Washington DC for $144 per night for two nights, they booked me for $291.80 per night and charged my credit card at that rate. When I discovered the problem on check in, the clerk told me that if I walked in off the street, the room would only cost $159. Last minute Travel support by phone and web form was unwilling to even see this as a problem.