Have you ever had a salesperson in an expensive store treat you bad because you didn't look rich?

I went in a very expensive store today. I was just out running around after my exercise cl, so I went in to check out some jeans. I usually dress better and wear makeup and everything, but not today. I guess I looked like I was a bum or something, because the saleslady kept following me, but when I would ask her a question about some item, she'd just give me short answers and walk off to help someone else. And she was super nice to them... they of course were dressed up. When she would finish with them she would scowl at me like I was going to steal something. I thought 'maybe it's all in my head' and asked her about the availability of a certain kind of hoodie. She looked at me and said " I believe we are out of those right now, but you might want to consider shopping at Wal Mart". I was floored. They don't even have that brand at Wal Mart. What was this lady's problem? Why would she treat me that way? Anyone had anything like this happen to them? What did you do?