While it doesn't excuse Z1 avoiding you at all, you really should have been more on top of that after spending $16,000+. I would have dynod not only at their shop but soon thereafter somewhere else to be absolutely sure.
Sorry to hear you had to learn the hard way. Added to the long list of bookmarks.
Boycott AMS Products - Killing Z32 product innovations, one quickly copied Chinese part at a time. www.SoCalZCrew.com - Come find out how we do it in the West!