Company is not paying FNF

Dear Sir, I have joined Navigant Technologies pvt ltd 4th of March 2017 as a Customer Care Executive which is located in Gurgaon phase 4 , and I have resigned organisation 22nd of October 2017 for my personal reasons, After that I had completed all resign formalities then they said to me that after 45 days you would get your Fnf amount the I had nodded. And after 45 days when I went there so they taken my signature on Fnf letter, In the letter written was that No amount dues on the company etc. and when I asked Fnf amount then they said to me you would get after 1 week because their is some financial issues in the company so I said to them so why you taken my signature before provide me Fnf amount they reply me this is navigant rules, then after several mail and reminder they don't reply to me. when I called to them every time they avart's. As far as I know Fnf time would be 45 days but now 86 days has been past but I didn't receive fnf amount yet. I have some financial issues so Kindly suggest me what action Should I take towards it. Thanks & Regards Rashid Ali Contact No. [deleted] Email Id : [deleted]