School not giving response for FnF settlement documents what can i do

Dear Experts, I was working in a private school in Baroda(Gujarat) as a Teacher. I served them for more than three years. After that I got one better opportunity than that. So I applied there and got selected. As per their concern they were telling they can't relieve me because I have signed consent form for the next academic year. So your resignation is not accepted. I was ready for all kind of procedure to leave the job. But they said the same thing every time. After few days, they convinced and said pay Rs. 50,000 as per your appointment letter clause for termination. We will relieve you and proceed for your FnF settlement. I paid 20,000 on the same day as they discussed and 30,000 paid after 3 or 4 months. Now after 8 months of payment till they had not called me or send any FnF settlement, my experience letters, few original documents. So I need help with this matter. Kindly input on this issue. What should i do ?