I used support@zhihaihe.cn for contacting them due to a firmware issue. The same happened to me: they didn't answered my email.
After a week I tried zhh19@zhihaihe.cn and this time I got a reply. (But they didn't show any interest in resolving the problem though. I have a thread in this forum explaining everything. Maybe it could be of interest to you).
If you still receive no answer, I would suggest you try contacting them through their Facebook page.