Wrong Item Delivered

Wrong Item Delivered - I couldn't find my size at the mall so I decided to order it online they sent me the wrong boot and weren't helpful to send me the right item all they could say is I must go to the store for a refund but I want the boot I ordered and I had to pay R150 for delivery. I asked if I can order it again and they deliver it for free no they wont be able to as if it was my mistake that they sent me the wrong Item, such bad service