As I recall, I saw your post on Bitcoin Talk. I'm sorry you haven't been able to resolve your issue yet. It seems you've lost your funds and they won't refund you anything.
Unfortunately, I have no advice for you, as you've contacted support and submitted all the required documents, and they still haven't resolved the issue.
What bothers me, however, is that BestChange has a good reputation, yet they still list suspicious companies. As far as I know, this isn't the first time.