Full and Final settlement

Hi Experts, I was working at an organization in Gurgaon and it's been 4 months I have left the organization. I have been doing regular followups with the HR team and I have just been getting run around for my full and final cheque issuance. After multiple follow-ups I was given the cheque issuance date for my full and final as 15th December 2015 but on 14th December around 10.30 PM one of the HR executives called me and says that the cheque issuance date has been deferred. I told them that I lined up my payments to be done based on what they committed for which the HR executive said that he was asked to communicate this to me by the higher management. When I asked him what would be the next date at when I can get my cheque, I got a reply as it would be confirmed to me after couple of weeks when can I get my cheque. I got the same reply over email from the Senior Manager - HR too on 15th December. I have shifted to Bangalore. Please guide me know how can I file a suit or send legal notice to my ex-employer so that they can issue me my full and final cheque without giving me further run around.