Yea, I had a similar problem with their Cessna 337 and O2A. They sent one e-mail telling me it was basically my fault and never answered any more of my e-mails. I don't buy FSD anymore.
If you did not receive an email in reply to an inquiry it is very likely that we either did not get the inquiry, or that our reply to you was culled by a spam filter. We do not simply not reply.
If you continue experiencing a problem with any of our software you can always send me a PM, or email me at td@fsd-international.com. I will be more than happy to see if we can help straighten out the problem.