Owner not returning the deposit and police couldn't help

My agreement had expired and the owner did not renew it despite having asked him multiple times. Also there was a rent increase which was more than 5% as mentioned in the agreement. 4 months (after 11 months agreement) I stayed without the agreement. During end of third month, I informed him that I will vacate in fourth month and did so. While vacating he was arguing that as per the agreement I should have told him 2 months before (but note the agreement has expired) and now he's not returning 1 month's rent amount from the deposit. Also I went to the place and saw that he has got a new tenant already who came in the 5th month (after I vacated the place) After he refused to pay after asking multiple times, I went to the police and they visited the place but the owner refused to pay. He told in front of the police and me that go file a case and he'll see. Later the police told to give a complaint in the police station, I did so but no outcome. What should I do now? Please help me as it's my hard earned money and really matter to me. I don't know if court would be a good idea + I don't have money for lawyer, court etc. Is there any way I can get the money back or it's gone? :(