How to get back our flat from Cooperative Society people

Hello Sir, I am a senior citizen widowed woman with one unmarried daughter. My mother in law had a flat in Golfgreen Kolkata. It was a Cooperative Society flat which she purchased in 1980. A share certificate was issued under her name. Sir but now the Original deed of the flat is missing. My mother in law passed away in 1994 and after that my husband used to take care of the flat and pay the maintenance. The flat at first was a one room flat and in between 2010 to 2015 extension of the flat was done to two room flat by the Society. I myself had payed through cheque and even have the bills with me. My husband passed away in 2016 and after that many Society members began tormenting me and my daughter in many ways. There was tapping of my electricity and so I had to pay huge electricity bills every month inspite of nobody staying in the flat and in many other ways. Sir, due to COVID from 2020 to 2022 I didn't visit the flat. At the beginning of 2023 when I visited the flat to my astonishment the flat was totally dilapidated. All the glass windows were broken. All our belongings were on floor. The Society even had put out our water supply. When I had compained to the Society members they didn't care and in turn began pressuring me for money and to sale the flat to them in that condition. At this I got disgusted and didnot visit the place after that. About one month ago the Society called me up and told me that my flat has now become infested with rats and insects for which the neighbours are getting bothered and so I must immediately come and clean my flat. I must also bring the papers of the flat with me. Sir as you know that the original deed of the flat is missing. Now I have the xerox copy of the share certificate under my mother in laws name, the bills of the extension of the flat I payed for, some maintenance bills. I also had Affidavits from first class magistrate to prove we are the legal heirs, Legal heir Certificates from local councillor. All these I submitted in xerox copy to the Secretary of the Society. At first the Secretary didnot say anything. I appointed a labourer and began to clean my flat. When the cleaning procedure started the Secretary called me up and began misbehaving. He told me that how dare I enter the flat as the flat is not under my name. I cannot produce the original deed so now both me and my daughter are outsiders. These Affidavits and Legal heir certificates are not enough to prove that we are heirs. In this way that day passed. Sir the next morning these people put the flat under lock and a notice was put outside stating that the lock was put to prevent illegal occupation of the flat. If the legal heirs try to enter the flat it would be complained to law enforcement office. Sir my question is 1) According to the Secretary we are outsiders and without original deed have no entry to the flat. Is it true? 2) The Secretary put lock outside the flat without giving me prior notice. Is it right?