Owner not retuning deposit amount

Hi, We stay on rent in Mumbai & our owner is in London & POA is given to her Brother in Law who is very much in Mumbai. We had a rent agreement done from Jan 1 2016 for 22 months & owner has decided to terminate the contract in Feb 2016, we have made our rent agreement online through agent with POA's signature. We were to complete police verification also but before that it got decided to terminate the contract as agent took the money inclusive of doing police verification which he never did after taking the amount from us post which we conveyed the same to owner & she mentioned again deal with third person & he declined to share the police verification charges as stated its tenants job to do it entirely. Here there is a third party person involved by owner & has been interacting with us since day one & also has been misbehaving while talking to me & my husband because of which we complained the owner about his involvement not being required in the same but owner has declined our request & says I will not be getting into this..third person itself would deal with you & also we cant be contacting POA also directly. Since things dint work out with the third person, he (third person) & the owner decided to terminate the contract. Now we have asking for our dposit of 85000 back & they have been denying paying the same at the last day. They say you will be getting the entire deposit only post you vacant the house & handover the keys to me (third person). We have been requesting them to pay us 75000 now as we have to pay further & rest 10000 you can keep the security deposit & inspect the house & adjust the utility bills & return by end of the month. We tried contacting owner & POA and no one has been supporting so far in the same. Third person has clearly mentioned he will not allow POA to come at last day & inspect the house as he would be doing it & collecting the keys from us without paying the single rupee from the deposit. We have been very clear that we will be handing over the keys only to POA after he inspects on the same day post we collect our cheque/DD for 75000 meanwhile. They have declined to disagree on the same constantly. Also the termination contract was communicated over whatsapp wherein we now are thinking to send the mail to the owner for the same to have it documented properly. Third person still continues mentally harassing us on day to day basis stating I will evacuate you guyz from the place immediately & destroy the house completely & have many ways to get into the house..i can also break the door if required. If you guyz have to take legal route you can but that is not my route..my route is different & I know ways to empty the house. He has been threatening us almost daily. Owner & POA are not supporting us at all. Kindly advise next step on the same urgently.