I have to agree that being a jerk to front-line staff who are trying to be helpful, but may not have the tools or knowledge to do so, is a douchebag move. Further, it is usually those who have so little control over their own lives that the low-level staff at retail stores are the only ones they have the ability to berate. If the person is rude to you, that is one thing. Otherwise, take your issues to management or corporate. Those people don't get paid enough to even get proper training, much less take a bunch of crap from dickheads.