An update, after waiting a while longer I contacted the vendor to say I had given up hope of it arriving, so I asked what they would like to do about the situation to which they offered a refund. I left it a few days longer then contacted them again to say I find it unfair really that both of us lose out to post office incompetance or dishonesty. In reply, I was contacted to say that the parcel had turned up, as returned to sender, so did I want the item or a refund, to which I have opted for the item to be sent again and this time I am sure it will arrive and in good time
Now, if I was an overly cynical person, I would say the parcel was never sent due to the vendor believing he could get more for the item, but that's the chance one takes with ebay and auctions and auctions that end so close to xmas.
Interestingly, though the snow was mentioned as a possible cause for undelivery, where the item was coming from and it's destination escaped much of what other places had.