We have an 04 Megane 1.6 Dynamiq. It went in to Mr Clutch to have a clutch and oil seal replaced. Since they did the work it's been pulling to the right under acceleration and then snaps back to the left when you let off. It's been back to Mr clutch and they have checked everything they can think of including...
Taking the gearbox apart and checking it
Checking the sub frame
Cross measuring the chassis and wheels to make sure it's straight.
Swapping the wheels front to back.
4 Wheel alignment
Checking drive shafts are fitted correctly and in good shape
Checking the diff is working as it should be.
They can find nothing wrong and I now have a car that's un-drivable!!!

Has anyone come across this before with a Megane? Is there something odd about the setup of these cars?
HELP!
Thanks, Rich