In Europe with integrated POS the cashier may be telling the truth:

http://www.flyertalk.com/forum/franc...lafayette.html

Best recourse is to raise a chargeback request with Citi, and Citi really follows through instead of paying out of pocket.

Yes DCC has awkward social/inconvenient environment going for it. I've stopped a boat from departing to stop it, moondog got dumped by a girl in stopping it, but we really can't do this all the time, in which case chargeback is the next best recourse.