I would ask them for a partial refund, offering you a discount on the next service !! (your not going to take it back to them again are you ?) whats the point in that your pissed off with the job they have done,and your not going back. I tend to steer clear of main dealers, mine is out of any type of warranty now, so tend to go to a small independant workshop, who offer a much better service and in most case's have genuine passion for the job they do. Hope you get it sorted soon.
