As far as customer service stories go, this is some comedy gold. Our friendly and knowledgable Subway employee found himself making a "Veggie Delight" sandwich for a vegan customer who didn't realize that mayonnaise was NOT vegan, because it has eggs in it. Sometimes the truth hurts, and it sounds like it was a bit of a bummer for this vegan. I mean hey, knowledge is power. You live and you learn. 

Vegan mayo - Text - Me: "Thank you for coming, have a nice day!" She just looked at me, sighed, "yea, 'll try" and walked out. And that's the story of how I taught a vegan mayonnaise is, in fact, not vegan.