Looks like I won't be getting my car tomorrow after all.

Got a call at ten to five today saying that they were unable to tax the car because the private reg nominee form hadn't been sent to the dvla.
I handed the form into the dealers on the 17th of May and it's still there just now. Told the guy that it wasn't my problem it was theirs and they would have to do something pronto.
Was told that they will phone me in the morning after they try and get someone from vw finance to change the plates on the car to normal ones until they can get the correct documents from the dvla but it's highly unlikely that I would be able to get this done tomorrow as only so many staff work at vw finance on a Saturday and the fleet dept is closed. If this fails they are going to supply me with a courtesy car at their expense.
I wouldn't mind so much but I asked the fleet manager 2 weeks ago about the plate transfer and was told that they just do this on the day before pickup.
He better not be there when I go through tomorrow or I will end up in court Monday morning. Absolutely raging with them.
What sort of compensation should I be asking for?