Unexpected long delay with paper review and no answer from editors
First thing first, I would suggest planning to never submit to this journal again.  Some journals take a very long time to review, and in some fields more than a year of reviewing is not uncommon.  Editors, however, should be reasonably responsive to email and months without reply is not reasonable.

Although, there is one case where it might be reasonable: it might be that all of your email has been going into their spam filter.  You don't say where you are from, but there can be problems of this type: I recently had an experience where some international colleagues had their entire domain blacklisted by anti-spam systems and it made every interaction very painful and difficult.

Either way, at this point, you've basically got two options for escalation in attempting to find out the status of your paper:


Make contact via another medium than email, preferably by phone so you can get a human on the line. 
If that fails, get in touch with the publisher and let them know what's going on with their journal.


You also need to be more persistent in your attempts to contact: emailing once every two months and just taking no response as your answer is really letting things slide.

If all of this fails, then you're stuck with an unpalatable choice: leave the paper in limbo or withdraw.  Neither is a particularly good option, but neither is the end of the world, either.