They want you to make a tight right-turn and go back to the Service Department so they can fix it right. Pre-delivery PREP should have caught that right away. If it were me, I'd get on the phone and lie. Tell the dealer you tried to stop but ran over a crosswalk full of nuclear physicists. And would it be OK if you forwarded his home telephone number to all the lawyers and cops.
If indeed sold with disconnected brakes, that really is an unforgivable act of negligence.