I don't think entire groups of adults would snob someone, surely? Maybe I'm just being optimistic here, but I find that when I have felt that way in the past that it's usually of my own making, i.e my assuming they are all being bitches or snobs when they are just in their own little worlds. I think we tend to worry too much about what we think others are thinking of us, when they are really spending far more time thinking about themselves anyway.
If they really are genuinely ignoring you, it often stems from some sort of insecurity with women, so it seems to me. I would ignore them back.