renault scienic auxillary belt ( fan belt )?

the fan belt ( auxillary belt ) snapped on my girlfriends renault scienic , we fitted a new one but the car woulnt start , its a 1.9 diesle on a 53 plate, the car is now in the garage being stripped they say it has damaged the big end bearings ,the valves and the bottom pully which has done more damage to the cylinder head. is this possible ??????? or could the garage be pulling a fast one ?????????????