I am working in agriculture department on contract basis from last 3 years

Respected sir/madam, My name is sameet vernekar and I am been working in the fertilizer control laboratory as a laboratory assistant which is governed by agriculture department of Karnataka from last 3 years on contractual basis. But in my work period I haven't got my salary on monthly basis i.e. I get my salary after two months or sometimes I don't get salary for 2 months and in the 3rd month they credit salary of one month. Secondly I am not given my salary slip even after asking them repeatedly. If i ask the second division clerk who manages the outsourced employee he bullies by asking why you want the salary slip even if we ask him about the EPFO details he doesn't cooperates and if we insist he tells us to leave the job. My question is what can i or WE (because there are many of them like working there and this is the same scenario with them too. Kindly guide to what we can do where we get a solution regarding this.Thank you