Next time AJ - if these are regular servers that you know or go to often - joke with them and say, (waving in the air) - hey, hi! What am I chopped liver today?

Sometimes humor and sarcasm can be used just to alert people to how their unthoughtful behavior is coming across...

It could have been they just didn't even notice they weren't acknowledging you - but it also gives you voice to tell them: hey don't be rude!

Just my .02