Landlord not returning Security Deposit

Hi, I moved to Hyderabad and took a flat on rent, I paid an amount of Rs 30000 security deposit through UPI and 15000 Advance rent. The owener said he will make the agreement document in few days and I can take the posession and start living in flat. After moving in the flat I started facing problems like water leakage from apartment above mine. After complaining to owner he kept ignoring and started talking to me in ill manner. I also observed there is termite in wardrobes, to which he just said there is nothing you are just giving excuses now. I decided to vacate and told him about this officially on a whatsapp chat. I said to me personally that he is not going to return any deposit and I can go if I wish to. I gave him official notice on whatsapp after 12 days of stay in this house. Problems I was facing were started after 3-4 days of stay. I vacated the house after completion of one month and demanded my security deposit back. To which he kept saying I will talk to you later and now saying he will not return anything as I have left before 11 months. How can I get my security deposit back. Please help and guide me.