Well I do a lot of research and when I go to places like PC World I am pretty informed.
My local PC World has some very knowledgeable people who did not bull!!!! me, indeed one even solved a rather irritating computer problem that I had been wrestling with and trying to find a Google answer to.
Nobody dispues that there may well be those whose knowledge may not be as good as one would wish, but to denigrate every employee, and indeed the Company, and indeed to suggest improper business practice on a public forum is either very brave or very foolish.
If you believe this to genuinely be the case then there are legimitate ways of taking matters forward, such as the local Trading Standards/OFT.