Waiting from last eight months for review comments. No reply. Want to submit to some other journal.

I submitted a manuscript to "Chinese Society of Mechanical Engineers (CSME)" in Septembet-2016. The status is "Under Review" till today. I wrote several emails to the editor requesting to let me know the status. But no response. In April-2017, I lost patience and I wrote to the editor and have clearly mentioned to consider this email as confirmation of "withdrawal". For that email also, there is no reply. Few days back, I sent Fax also. Again no response. Can I submit the manuscript to another journal ?