My landlord not return my advance back.

I rented a 1bhk room on (date) near amruthanagar . I paid 40000 advance and as per the owner room rent is 10000. I was giving him 10000 every month before 5th. And also I send him the screenshot for every rent I paid and he said ok...after 6 month, he is saying "room rent is 11000. Where is my rest of the amount ". I thought misunderstanding happened then I told me for 6 month you can cut 1000 from advance. And also I told me next month I will vacate and he insured he will pay my advance after the maintenance and that 6000 deduction..I agreed with..But when I vacate first he told I will give by evening. In evening when I asked he changed it to next morning. Next morning he send me few calculation he will pay 20000 to me...Sp today I asked for the money he just denied to give me..and keep harassing me. I have all the proofs for all the conversation And also I have the bank statement whatever I paid to him. What can I do ? Also now I'm in kolkata, the incident happened in bangalore.