Complaining about woolworths Cavendish square Cape Town

On the 23rd i purchased a dress which I 1st tried on the dress before even purchasing the dress. Purchased the dress to wear it on a funeral the 24th ,however I ended up wearing my old dress to funeral due to weather conditions. So I decided to return the dress cause I sore no need for me to keep the dress. I get to the store to do an exchange of the dress and I was informed by Mr Marlene Bredekamp (manager) that they can't take the dress because it has marks. Yes the dress has a mark but who's fault is that? The dress was never worn irregardless of the mark or not so why can't I return their dress? I think Yall should close down fitting rooms to avoid us clients or customers trying two fit anything maybe than all the items will be clean. 1 of the items that I have wanted to purchase had huge big stains but that was in their store, how convinced that is.