OP you don't mention the mileage of the car or whether it's petrol or diesel. These three pieces of information could be critical to establishing the source of the problem.
Modern cars have certain "disposable" parts and their useful lives are defined in both kilometers / miles driven from new and their age e.g. 100,000 kms
or 4 years, which milestone is reached first.
Amongst the items that are "disposable" in this way are the drive belts (timing belts), auxiliary belts (water pump, A/C) and the water-pump itself which can have a plastic impeller which can break-up with age.
Other possibilities on a diesel car could be the clutch and the dual-mass flywheel.
Any of the work above will normally result in the removal of certain engine mount bolts. Those concerned with the works I mention above are referred to as "stretch bolts" and they must be replaced with new bolts - VW workshop practices and safety considerations require this. The bolts are part of the energy absorbing safety features in cars and when tightened to the appropriate torque they "give way" under certain pressures and in a set sequence to protect passengers and to help prevent the engine / gearbox entering the passenger cell.
"My husband talked to one of the Mechanics in the garage and he said that the bolts were tightened. "
It is unusual that a mechanic would choose to volunteer this information as checking the tightness of these factory-installed bolts would not be a regular service procedure; therefore may we assume he was involved in replacing parts that required the removal of the originals and either new bolts were not used (as required) or the new bolts if used were incorrectly torqued?
All of which is pretty much by the by; you were sold a vehicle that was not fit for purpose (a reasonable person would expect it to be free from major defects, like the engine falling out, for more than eight months), so sue them
This is your friend and supercedes any warranty, or none as the case may be.
Were you told of any major service items being undertaken prior to purchase?