[Porsche-O-Phile]

You're actually doing them a favor by wasting their time. Most are robotically connected to auto-dialers for their entire shift (a friend of mine used to do it while in college); if someone hangs up on them or whatever, the system immediately connects you to the next number in the database without any interruption - and so it goes, one after the other after the other after the other... for your entire shift. If you're sitting on hold waiting for someone at least the guy making the call would get a few minutes of sanity (also the side benefit of costing the employer/marketing company a few bucks) so I tend to think this is the most humane way to do the most good and deal with the situation. Help the poor guy stuck in the ****ty job, do whatever damage I can to the marketing company bent on trying to waste my time.

Focus your ire on the source, not the employee. I like the tactic of putting them on hold for a while. Hell, those guys get paid (poorly) by the hour and leave at the same time, so the fewer calls they have to make the easier their day is.