Thanks to this forum and a few members that went out of their way to assist, we do have a refund.
ShinyShoe might be right in that it was holiday period etc.
I have spoken to the seller (he called me eventually) and maybe I am just a softie but he seems to be in some sort of mess at the moment. We all have points in our lives when it all doesn't go according to plan and life smacks us around a bit so I will take his word for it.
For this reason I don't want to name him or his business. I think it would be unfair if someone Googled his business and the only link they found was this article. It could be the end of his business. He does have a family to feed.
Would I buy from him again? Yes if I was in his shop and could see, feel, smell the product first. Would I buy online from him? Only with PayPal or maybe a credit card and I wasn't n a rush.
On the other hand, the purpose of this forum is to assist each other with information so I will say that if you are looking for aftermarket exhaust parts for a marine diesel and you have found someone down south, you are welcome to message me privately.
Please don't take guesses as I don't want the name of the business or the owner to be linked to this forum.
Yes it did take a very long time to get a refund and I still don't have a solution to fix my boat but I do accept that life is particularly tough for him at this point in time.
Once again thank you for the advice and also for those members that went out of your way to contact him on my behalf.