Stamp duty paid agreement missing

Dear Sir/Madam, My name is arif khan & i am a resident of mumbra thane, last month i purchased 1 flat in a co operative hsg soc in mumbra,all the agreement work done i.r agreement for sale at rs.100 stamp paper,power of attorny,no objection certificate,naa harkat dakhala, society transfer doc form, i have received all chains of doc from builder agreement first owner after her death thier legal heirs doc and second owner sale deed,share certificate and required doc. Now when i went to transfer my name in chs treasury officer told me your doc is not sufficient to transfer name, you don't have stamp paid agreement for sale document which is important from whom you purchased flat, society member has shown me 10000 paid stamp paper agreement xerox, I rang from whom i purchased flat he told me i don't remember exactly but after 2 month of his buying when he went for transfer the society told him to make stamp duty paid agreement which he done after 2 month and he don't know where he kept that stamp paid paper now he told me it is missing because he shifted his flat lot of time. He told me to make legal procedure to get transfer in your name, now i have given to the lawyer for new agreement stamp paid for Rs.10000. My query is do i need to take out registered document from registration office of first owner from builder bcoz i have only builder agreement. i have share certificate (what is the value of that) do i need to make police complaint FIR along with whom i have purchased flat. do i need to give public notice how i will become member of the society Thanking You