Home Depot - Baseline - Ottawa

Usually I get good service at home depot (Ottawa, Baseline Road) in any section. Unfortunately today was different. I asked a rather simple question to John D. in plumbing about the difference between two toilet fill valves that were very similar, one of them claiming to save water (?). His answer was 'read the label' (sic!). When I insisted he just mumbled some explanation to get rid of me. I found his behavior very rude.