What to do if your employer doesn't pay salary

Hello Sir,

I am working in the UAE as a Telecom Engineer (but visa as an Electronic Exchanger). My company has no project since Feb 2017. They asked me to go on vacation in Feb 2017, still, they didn't get any project.

I came back on July 13, 2017, without informing them. Now they are not paying my salary as there is no work, so I asked them to provide NOC so I can find other jobs, and now they are asking for visa amount. WHAT SHOULD I DO NOW?

Visa issue date: June 2016 (2 yrs employment visa)

Please suggest me what to do.