Did you use a rate code that brought up a statement that said "Do Not Use --to be booked only by Hotel" or some such thing?
Is that why you are leaning to canceling the other reservation -- that you have some suspicion that you booked a rate that should only be booked directly through the hotel, and with the hotel management's permission?
Are you divulging all you know about how this rate came about to this board?
Have I hit the nail on the head?