Refund refused for sub-standard clothing

My daughter bought two tops at Jet. She threw away the slips as there was nothing wrong with it and proceeded to wash it per the instructions. The tops shrank by more than 2 sizes. When she went back to Jet they refused to refund her even though she showed them by how much the tops shrank. They said she "had to have" the slip otherwise they could only exchange it. She didn't want anything else and was therefore forced to take the same tops again, which she knows will shrink in the wash again. Needless to say she was very disappointed because she wasted money on extremely poor quality products and there is no way to know if their other clothes are also of such a poor standard. In this case I feel a refund is called for because they had the actual evidence in front of them of the poor quality merchandise they're selling.