I got a quote from heating engineer saying that se was going to replace old copper heating network by new copper tubes. I came home and found out that he was replacing copper by plastic. He wrote copper in the quote. Now he says that it was a mistake and he actually meant plastic. I would never replace coper tubes by plastic but how would I know that he was going to use plastic if the quote said it was copper? He refused to use copper and took away old tubes saying that he recycled them. What can I do in this situation?