OP is touching a point which I know a "friend" that tried it with a certain airlines point program twice, and got his points back. I however advise against it as it's blatant fraud. I don't however think this can be done with revenue bookings. Not worth being in "Lucky's" shoes for such a long time.
I did notice another interesting thing. Aeroplan now allows cancelation within 24 hours. Cancel button disappears once checked in.
I'm kind of shocked to see such questions, with the idea of the OP that's straight out gezel, for the same price does he/she go shopping in the grocery and snatch a pack of gum here and some candy here?
Flying a leg of a flight and the stewardess spilled the hot water all over you or they damaged your bags, or a 7 hour delay then I can understand from where your coming from and requesting some sort of compensation ,but to outright go and gyp a company where you know you got the full service and realize there's a loophole to take it all? What's going to be after 120 when you come up to heaven? What you going to say then?
Yes many things that you might find here is not the most kosher but to straight out steal a cookie?!
As much as the target deal seemed like pure gezel I spoke it over with Harav Shloima Miller who said what was ordered is fine and didn't recommend to continue, but said it was fine.
Even HC might not seem the most kosher viyosher but your still paying for the flight and giving them an open seat for the overbooked flights they always manage to do.
There's a path which is a gray area and then one black and white! I'm sure you guys can figure which one this is.