Thanks for the laugh KiraNarise, I'm going to use your way.

Works better than using a foreign language and pretending that you don't understand. Why? Because, 1) this one time the agent understood and I had to recover quickly and 2) they get too sympathetic and start rebooking everything then I have to revert to English and make up some other excuse

I've tried acting kind of cuckoo and it seems to work most of the time. But, of course, it does nothing for my self esteem