The issue was a connection problem to the DNS servers from our client area. That issue has been fixed now, so you should be able to obtain your SSL certificate now!
Thank you for your answer.
There were something wrong, i tried some thimes and then i got one SSL certificate. but i could not installe it successfully.
I tried some times again, and installed it.
Web page can be opened with a ssl lock now, though there is a problem from sslshopper.com