Two Right Footed Boots each different size

On the 2nd May I placed an order on line for Blue leather boots R599. I received them a month ago. I got 2 RIGHT sided boots each one a different size 39 and a 41. I wrote to them wanting a refund to my visa card. Today they offered free boots but i must pay shipping. I want my money back as going overseas and i dont get answers quickly. Can you sort them out please. Dreadful service and not my fUlt. Leather is suspect.