Company not paying my Salary

Hello, I was working with Rediscover Clinic in Delhi for last three months.They have around 19 Clinics in Delhi. On joining they had not provided any letter stating that the company would give it after 6 months.. My Aug salary was transferred in my bank A/c, In Sep,the salary was paid in cash on 31st Oct. Please note All the staff got salary in cash. So in starting Nov only I had started demanding my October salary, suddenly on 7th Nov I was informed that salary of Oct would Only be paid if sales target are met by Nov 20th. If not then October salary would not be paid and 20 to 25 Nov was out of question. On raising questions on how could someone implement a new rule in Nov and stop salary of OCT I was told for separation immediately by them also adding Oct salary would not be released. Since then the Company Head Dr. Kukreja has stopped taking my calls, he is reading my Whatsapp messages but not replying to them. I was working as ACM with salary of Rs 40000/= and I have record of some client invoicing and dealing done by me (on their bill vouchers) till 5th Nov. Please suggest what could be done to get my salary for Oct 2016.