Since everyone is still here:
1. Tell them that you got taken, but that because not enough people showed up, the event was cancelled and everyone got a refund.
2. When they get all skeptical, ask them to prove that it's not true. Point out that obviously the criterion are different from what they were led to believe, since they didn't get taken.
3. Tell them God has a personal message for them: "Stop being a schmuck!"
Use your own personal version of Pascal's Wager - "If I'm lying and you believe me, you've lost nothing by not being a putz, but if I'm telling the truth and you doubt, you've lost everything. So do yourself a favour and stop being such a smeg-head!"