I highly recommend the article from David Pogue available here.
Ironically, today's Dilbert strip touches on a similar issue.
Both of these touch on what Pogue calls passive agressive robbery, the fact that if there are problems with a rebate, or a billing to a health care provider, that most people will only pursue the issue so far.
I've been burned by this time and again. I stopped shopping at Circuit City because twice now I've bought items counting on a rebate that never came through. I think that this will be an increasingly common problem.