Landlord illegally running a PG and now not returning my Deposit

I was staying at a Paying guest in Mumbai. The owner was running PG without taking prior permission of the society. Also, neither any police verification was done, nor there was any agreement. Earlier the owner's wife told me that their family does not live in that house, and that they will be moving to US very soon. But after I shifted, I got to know that even their whole family is living in the same house. As I was not comfortable in staying with a strangers family, I told them that I want to move out. He told me that I will have to serve 1 month as notice period or else I won't get my deposit back. When I told him that if he does not return my deposit, I will have to take legal action against him, he got furious and told me to leave the house immediately without letting me take my belongings away. I went to the local police station immediately. The police told him that since he was running PG without society's permission as well as without Police verification, he would be in trouble if he doesn't return my deposit. But at the same time, the police told us that this, being a civil matter, the police cannot interfere in between. It has been more than a week and I haven't received my deposit yet. The owner is now accusing me that I damaged his geyser, so that he does not have to return the deposit. Also he is saying that since I did not serve the notice period, he will not give me my deposit back. As a matter of proof, I have a letter given by the society to the owner to vacate the PG within 7 days. The deposit amount is Rs. 5,500 and the rent was Rs. 7,500. Please advise me as to whether I can get my deposit back.