Thanks for the replies. 
I can't bear poor quality clothes and I'm a bugger for not returning things, even when the postage is free. There's a big time overhead repackaging things and then going to queue at the PO, etc, I mostly put it in the Oxfam bag. I'm beginning to buy less online as so much of it is a miss, for which I don't seek recompense.
I don't know how many of you do that? It's a whole other thread really.