I'm really surprised and feel sorry that you haven't received yours at this time.
Got mine yesterday from MacConnection - ordered two days ago with the memory upgrade! I originally ordered at Amazon. com on March 1st, then I canceled and reordered at MacMall on April 1st and after I was told that they could not ship me anything till April 29th, I canceled again, and called MacConnection who advised me that they have quite a few in their inventory and filling orders with 1to 2 days delivery dates.
I am sure you have other Mac stores in UK other than those jokers you are dealing with. You are the CUSTOMER, YOU have the money, so tell them to go to hell and go to another place.
You are really missing out bruddah. This is one beautiful machine.