All three times that happened to me, I was so taken aback that I didn't say anything. Believe me, I'm no shrinking violet, but when I'm shopping alone I tend to be in my own little world til something jolts me out of it. I went shopping for carpet not too long ago and the salesman was so rude to me, behaving as if I was annoying him by wanting to spend my money. I turned abruptly to leave, but stopped to tell the manager that he might want to find out if his salesman was really interested in making a sale or playing pocket pool!

People who have not been overweight do not realize how differently you can be treated because of your size. And in case someone would think I'm over sensitive, I believe I can tell by others' facial expressions, tone of voice and other ways when I am being dismissed because of my appearance.
While Christmas shopping this year, a young, slender salesgirl actually smarted off to me because I asked her a question. She was standing there filing her fingernails when I so rudely interrupted. She could barely stand to wait on me. I went to her manager and explained what had happened and why I would not be making the IPod purchase I had planned. The manager stuttered around but did not even agree to speak to her employee. She finally offered me a discount which I refused (I found it online cheaper anyway!).
Sorry I went on so long, but it still makes me feel sad and mad. I may be wrong about sizism prejudice, but I don't think I am. I've been overweight too many years and been slighted too many times!
Lisa