Land owner harassment and not returning the refund

Hi, I have been living in a 1BHK in the heart of Bangalore since 5 years. As I am a Bachelor some how managed to adjust with the arrogant landlords. However have decided to move out of the premise and made it clear 2 months ago though did not confirm through any written notice. But had to put off the idea due to the official commitments. Also made it clear to them at the same time that I would inform a month in advance in case if I vacate. Unfortunately had a verbal altercation with them recently and told on the spot to settle my advance of 100000 INR in a month from the day. The issue now is they have been insisting for a notice of 3 months and are adamant. Though I had the rental agreement for the first 3 years, couldn't renew it thereafter. Moreover there is no mention of notice period to be served in any of the previous agreements. Recently I found out that the house isn't their name and the electric connection is not completely legal. Can that be of any help to me? What are the options do I have to get the refund within a month? How can I ensure that the lack of rental agreement doesn't create any hindrance in getting the refund? Kindly suggest the best options available with minimum legal procedures. Highly appreciate your immediate response.