Holding back my monthly salary by my employer

Sir/Madam, I Rajarshi Das Gupta, employee of an educational institute as an Asst Teacher, till now i have not received my salary of last month(April-2015). Every time i ask for my salary they delaying and telling me, i won't get my salary as i protested against illegal activities done by the management against students. Each month they pay my salary through Allahabad Bank, K.K.Tagore branch, Kolkata-6, West Bengal, India (My a/c no is 50030373281, IFSC Code is ALLA0210035 ) but this month they did not submitted my salary to the Bank, not even paid in other way. Luckily, i have collected my salary certificate of April 2015 which clearly indicating my salary of April-2015(I am sending this salary certificate as an attachment). They are simply cheating me and taking revenge. They also threatened me not to tell to anything in this regard to anybody. I am fearing to go to Police for my family's security as well as i don't have money to fight against them in Court.They also forced me to resign on 5th May, 2015. They also threatened me that they won't give my PF if i do not resign. I am very poor and i really need this money to run my family. Please do the needful and kindly help me to get my salary. Thanking you, Rajarshi Das Gupta 19A, Rajendralal Street Kolkata : 700006 West Bengal, India Mobile:8902425346 Email : rdg_21@rediffmail.com ---------------------------------------------------------------- My Employer's name and Address: Nopany High 2C, Nando Mullick Lane Kolkata : 700006 West Bengal, India Email: nopanyhigh@gmail.com Fax : (033)25437168