Auto body repair & detailing: Repair, mechanic, proof

Question
General question - if a mechanic cant fix your car are you still liable to pay them even though they did not fix the problem that you brought it in there for? and after they admitted they cannot fix that problem?

If its true that you don't have to pay them (minus any other labor fees) do you know where I can find proof that you don't?
Thanks
Bre

Answer
Bre......if the shop attempted to diognose the problem and spent time checking the vehicle over

then you do owe them diognostic time. They did admit that they can't fix the problem.

If you signed a repair order you are pretty much responsible for payment.