Can I help you?

Why is it when you are in a store of your choosing and having a difficult time of it a usually teenage employee of the store will walk up to you and say "can I help you" and then proceed to be of absolutely no help at all. In fact, after explaining your plight the employee will say something like " I don't work in that department, man" then take off to find someone else to hand you off too. When and if the new employee arrives he/she will not know either. If you are able to hang in without having to take a Valium the last employee will show up. The Assistant Store Manager. You will recognize the black skinny tie and wrinkle shirt. He or She will say we don't carry that anymore. At that point feel free to scream.