I've literally just joined up too after reading this story. I'm really sorry to read about this loss of a fine motor...
Before you contact VOSA, please check out the MOT status check online for the car to see if it's actually been tested.
If it has, please be aware that the 'person' who was actually testing the car is entitled to take the vehicle for a road test, not someone else.
If it hasn't been tested, or someone else took it out for a road test apart from the tester then you have a good case.
good luck matey