If your dad is anywhere near Newcastle, we'll replace his timing chain and service the car for him, and you wil get change from £300.
My techs can do these in their sleep, it's a very common failure.
I'm sure you would have change from £600 from a main dealer, someone is trying to take him for a ride.
This^ my Corsa a yearish ago cost me £220 for the timing/tensioner change.
It soon starts ticking again though as vauxhall are ****. I make it my goal in life to persuade people to buy something other than a Corsa.