Refund refusal after wrong delivery

Bought a double pot zinc. Product dropped was in my open garage during the day and no one signed for it. Found a box lying around at night and when I opened it was a single pot. Called Sunrose and was told to courier it back at my own cost and I REFUSED. Requested a refund and they refused. Forced to take this matter to my lawyers. Pathetic, arrogant high level of incompetency service. I WILL NEVER EVER BUY ANYTHING FROM THIS SHOP.