Rent not paid by tenant - how to recover

Dear sir, I had rented a flat to a tenant, who stayed in his flat in noida, for 4 months and 10 days. He didn't pay the rent for 2 months and 10 days, and we want to file a case against him. He has already vacated the house. While vacating he promised he would pay the remaining amount, but he has paid up till now. It's been over two months. During early days he used to pick up the calls, make an excuse and demand for more time. But recently he has started ignoring our calls. Please suggest, what steps should be taken to recover the rent?