Reading your post it seems that the vet had probably no idea what shivering was and had never seen it before rather than admit his lack of experience he advised the purchase, then followed this with incorrect information regarding ongoing treatment.
I think you do have a good case for compensation, insurance companies will often pay out rather than take it further if you have evidence that is indisputable, which I would think in this case you do.
Lets hope your right, I'm keeping my fingers crossed for a favourable outcome, it just doesn't seem right that we have to be put through so much stress first.
