Originally Posted by LondonElite

OP, I think you have a bit of a chip on your shoulder. Showing a credit card at checkin or at the gate is highly unusual in Europe (and North America) for the vast majority of flights. Personal data point: I log over 100 flights a year and the last time I showed my cc at an airport other than to buy something was on a Bangkok Airways flight from Koh Samui in 1999. I suspect that bringing up the question with a CSA phone agent was a bit like asking him him how much takeoff thrust he thought the pilot should use.

But all of this begs the obvious question: if you knew it was a requirement, why cut the card???