Lix you are certainly passionate about your causes, you should work for SPCA, or something like that.
But you also must remember, some people enjoy going into store for the specific purpose to tick sales people off. that is how they get their Jollies. Sad but true.
Try working in healthcare sometime, this is nothing, just wait, just wait. Witty's job as well, actually I think that is worse. Same as waiter/ess, some people just like to complain, even if it is about nothing!! They like to cause a reaction. Best thing to do is not react, or smile and be super sweet, takes away their fun.