Terminated without reason or pay

I am seeking your advice on my job. I should say ex-job. I was until last week working in an advertising agency. One day HE came to our Gurgaon office and on the same day in the evening she said that my performance was not up to the mark and she gave me the relieving letter and full and final cheque. This happened on 6th June. And on full and final cheque they gave me the salary for the month of May and June until 6th. And when I ask HR if my performance was not up to the mark then you have to send me the email first and gave me the chance to improve my performance but they didn't say anything. Moreover last year in Non'2017 they hold my salary without any prior notice when I asked the reason then they gave some excuses like I didn't mention in my Facebook and LinkedIn profile that I am working here so at that time I wrote an email to them that where it is mention in my contract that you hold my salary for this reason. And in that email, I clearly mention if you didn't process my salary then I am not able to come to the office and have to do some legal proceedings, then the MD reply the same thing that my performance was not good. But on the same day, they process my salary. Kindly let me know the way forward.