Qatarsim,  As per Labor Law (no14) 2004:

If they havent given you are contract: this is illegal as employers have to give you one. (Article 38)

If they are working without their sponsor's permission: this is illegal. Highly unlikely that a government employee would be allowed. (Article 42.3)

If they are not paying you on time: this is illegal. They have to pay you monthly. (Article 66)

If they dont repatriate you at the end of your contract (even if you resign), this is illegal (unless you want, and they give you, an NOC, so you can trnsfer to a better employer) (Article 57)

If you mean they are not paying End of Service gratuity, if the worker has  completed 1 years service, this is illega (Article 54)

I suggest you go the Labor Department, and ask their advice. What do you have to lose?