Rudi--now that's a really interesting strategy. However, I don't think it works. If you get the refund of the ticket, it is applied as a credit on your account. (Of course, if you cancel the account, they'd probably give you a refund check, but who wants to keep changing credit cards, just to get an extra 1000 or 2000 miles from this trick?)
BTW, THANKS for the great airport guide and the swiss chocolates from the December award. My wife and I have both appreciated the chocolates already, which just arrived today.