Eek. I'm sorry to read of your troubles at Lulu. Racial profiling, unfortunately, is a hard topic to change people's minds on. It's maddening to think that you can't do anything about what happened. Well, you tried, but as you said, it's so easy for people to fall into the pattern of thinking that 'nationality #1 did A, so everyone else will too'.

I guess the only thing you can do is not shop there anymore, and tell others about what happened. As you are here.