Very <span class="curse">p@!%!d</span> customer

I bought a pair of ballet tights for my daughter from them. I have told them that I was not sure of the size. Went home tried it on once and found it not fitting. When I went to return them, I was told that I was not supposed to open the package!!!
How do they expect me to know if they will fit? I have specifically mentioned that I might exchange them if they did not fit. The sale persons there did not tell me a thing about the policy. They even told me that sighs were everywhere while I could not find them when I tried looking around!!!