Unregistered society not accepting the maintenance

Respected Sir / Ma'am, Looking for your expertise for the case mentioned below. a) We are residing in one of the falts in unregistered society since 1985 & as due to society is unregistered the said flat name was transferred internally by society from my Grandfather to my Grandmother name and from my grandmother name to my father name by following the agreed process decided by the society with all written application copy with us. We also have all the maintenance receipt with us with the respective name on it. b) We have ongoing title suite into the city civil court since 2009 & we are the defendant in the suit. I have below a few queries. a) Due to society is unregistered some of the self-so-called volunteers become the Adhoc committee members without following the process and declared them self as committee members and due to their some back support from undisclosed powerful sources no one is objecting them or complaining against them. b) Due to the ongoing suit, the advocate of the plaintiff sent a legal notice to our committee members to not to issue maintenance receipt on the name of my father which was issued earlier for almost 5 years. c) Due to the legal notice from the plaintiff advocate, our unregistered society committee member has decided to not to issuing the maintenance receipt to my father name which was not formally in writing communicted to us till now, even though we have repeatedly requested for the same. d) From post 10 years we have regularly sent maintenance to society members via Money order but they keep rejecting till date without any reason. e) We have also sent a legal notice to the committee member with CC to Police and other respective authorities but they also rejected the same. f) We then took police help, however, police comment is due to its civil matter we cannot help more. My Queries are As we have regularly paid our maintenance via money order and they have not accepted the same till now, however, the other side is they keep threatening us time to time to pay our pending maintenance on there own condition i.e. We will not mention the name on it and we will only mention the flat no i.e. also we will not accept the maintenance in cheque we will only accept in cash. In Mumbai to whom we can approach for complaint against our committee members for their malafied intention and to accept our maintenance and issue the maintenance receipt to my father name till we have any final order of ongoing suit from the honourable court. Or any other best suitable suggestion? Thank you, Kunal Shah