my article has been evaluated since 17 months. what do you think about this situation?
If they're not answering emails, that is a very worrying sign. I would suggest sending an email to the editor (cc'ing the editor-in-chief and any other relevant people at the journal) saying that you are very concerned that they are not answering your emails, and that if they don't answer this email, you intend to withdraw the paper.

Then, if they don't answer the email within a reasonable time, send them another email withdrawing the paper.