Very agry customer

I bought a skirt at legit highveld mall swapping my bank card on Saturday the 11 July 2015 roud about 13:42 without fitting it. When I got home I fitted and the skirt was small in a way that it just stucked on my hips. On monday the 13 I took back the skirt for exchange with the tag on and a slip. As the were no sizes any more I requested for a refund and I was told they giving refund on gift cards, I asked where is that written caused is not on their slips they told me is their policy which I was never told about when buying. The store manager even removed the string holding a price tag and the skirt told me she is not happy cause I took out the tag and worn the skirt,I asked how can I wear something small?I'm so very angry and dissapointed that the skirt is cheap that I could not do that or she knows from her that she buys to return. This was a very serious allegation to me,and I even think of suing her. I took the skirt that I am now running around with without help as I was given attitude and bad service.