How do I recover my consulting fee?

I work as a freelance consultant and provide development research services. The client in question (my old employee when I was working full time) and entered into a contract for my providing guidance to their research team in preparing 4 case studies. The client is based in New Delhi while I am in Lucknow. Following are the details of the contract: 1. In effect from November 20, 2014 to March 31, 2014. May be renewed by mutual consent. If not renewed on 31.03.2015, it will stand terminated. Either party can terminate the contract by giving a notice of one period. 2. Consultancy fee to be paid will be INR 5000 per day for working for a maximum of 3 days per case study. 3. The consultant will be required to raise a monthly invoice for the consultancy fee based on actual utilization of number of days after finalisation and approval of particular case studies. 4. There were three terms of reference for the work, out of which I completed two deliverables in a period of 7 days in all. Once I finished the work, the client started telling me that the work has been stalled and will hopefully be resumed sometime in the future. I called, emailed, texted etc to inquire about the work status as the end date of the contract approached but did not receive a response from the client at all. Finally, on the end date of the contract, I raised and sent an invoice for INR 35,000 for 7 days of my work. Since then, I have tried to reach the client multiple times but have not received a response. My payment is still pending. I would like to know if there is any way in which I can recover my payment in this case. Thank you for your help. Best regards, AD