I have been to look at the car and the valves have hit the pistons, ( no compression) taking off the cam belt cover there is still a belt fitted to the vehicle, removing the belt I could turn the camshafts and water pump and idler pulley so what I think has happened is they fitted a belt to tight, it broke, they collected the vehicle and fitted a new belt.
I did not touch the car, one of the workshop staff removed cover ect, if there was no belt they could say a stone must have got between the belt and a pulley, but I have never known anything to cause valve to piston contact, other than maybe reving the engine flat out standing still or incorrect timing when fitted.
Thank you by the way for your reply, it has answerd many questions what to do.