Membership in Co operative Society

My father (now expired) purchased a flat in the year 1985 in a co operative society in Kolkata jurisdiction. Consequent to the death of my father I am the owner of the flat in Co operative by virtue of the nominee declaration made by my father. Subsequently, in the year 1998 the same promoter who constructed the building was also constructing a new building complex Co operative Housing Society Ltd . The promoter subsequently approached my parents to intimate that a promoter-member due to the financial crunch was unable to purchase a flat measuring 1100 sq feet and that 50% of the remaining flat is available for sale. My mother (now expired) who over the period saved some money showed interest in purchasing 50% of the flat measuring 540 sq feet. As per the advice of the promoter, my mother made a false declaration that none of her family members owned any flat/house under the KMC locality. The promoter insisted on the same as there was no buyer for purchase of a small flat measuring 540 sq feet. The decision of segregation of the flat into two halves was also approved & passed in the Managing committee meeting held on 8th January 1989. Subsequently, the flat was allotted in my mother’s name & deed of conveyance was issued in my mother’s name. A written membership certificate by also issued by the then secretary. Subsequently, due to dispute with the promoter with respect to short measurement of the flat, the promoter through an anonymous person made a complaint to the co operative society about the ownership of a flat in the name of my father. Consequently, the Deputy Registrar cancelled the membership of my mother vide letter dated 19.03.1991 & 01.09.1992. In the meantime, on receipt of the letter from the registrar of the Co operative Society, it was also intimated in the letter that the prime reason for cancellation of the membership was due to non receipt of the approval from KMC in respect of the separation/segregation of the flat into two separate units/flats apart from the false declaration made in the affidavit by my mother. This mistake was committed by the then managing committee who separated the two flats without obtaining approval from KMC. In the meantime numerous communications & letters were issued to the managing committee but no plausible answers could be obtained from them except intimations to vacate the flat. During the intervening period though the membership has been cancelled, the co operative society continued to collect the maintenance charges & the proportionate share of repair of the building, plumbing & installation of the deep tube well charges. At present the flat is under lock & key & under the possession of myself. I intend to know the possible outcome of the case as either I want a membership in the co operative being the only legal heir of my parents or dispose of the flat at current market value and under which provisions of WBCS Act & Rules are applicable. REQUEST YOUR VALUABLE ADVICE ON THE MATTER. PL