Yea, I would have just said "Wow, congratulations!" and kept on playing.

Back in the 90's, my friend and I had taken the shuttle to the Gold Coast from the Strip, specifically to sign up, get free play and play their massive amount of VP machines.
We were just about to sit down and start playing when this lady comes up to us and states "Ya may as well turn around and go home, these machines aint payin' today!" Oh, okay! Ha Ha!