It's a bug. It was explained to me some time ago that the discount shows up on your finance page and takes effect for you when you order lots of planes, but that the hacker alert doesn't really notice the discount. So buy a few less until it gets fixed someday.
They never made money at the end of the last round either, right before the reset. I have the same problem can't open a route with a big jet - can only replace aircraft and make money. I'm guessing its a bug.