I always just had to be persistent. If the emails were given the shuffle off a phone call to customer service has helped at times.
There were a couple of times that having a lawyer as a friend helped as well...
As I have mentioned before on this board, I like Snappy tools however they have the most inconsistent warranty determinations possible.
If they keep trying to shuffle you off on the driver try getting the district sales managers contact and dealing with him.
From Snap-on's web site "To obtain warranty service, return products to Snap-on or a Snap-on dealer. By repairing or replacing a Product, or providing a refund, Snap-on does not waive a claim that a Product nevertheless has been subject to abnormal use."
Make them live up to it.