So this was in a container and they're taking the container off the ship at Southampton and then taking it to MK to unload it ... so you can't pick it up from the docks?
What a shame ... they must be able to sort something, surely? Otherwise, you're going to have to then pay to get it take back to where it was! I suppose that's the downside of containerisation against RoRo (which I would have done I think - it's hardly as though you'd be worried about the paint getting damaged).
Just sounds a right round-the-houses-job! £££££ for you, unfortunately, unless it's a to-the-door price you've agreed. I think it cost me £180 or something to get my 240z brought to Peterborough from Felixstowe.