Conveyance deed matter

It is a matter of conveyance deed to society where builder has failed to do conveyance and hiding behind clauses in agreement of sale. Brief facts of the case: Housing complex had 3 buildings. Building A completed in 2002, building B in 2005 and building C in 2010. Builder registered housing society in 2003 and gave written undertaking to registrar of societies that he will convey land and building to society. At time of registration of society no individual sale deeds were made and no such sale deeds were made till 2010. But after selling all flats builder began making individual sale deeds with some members without informing society or taking NOC from any of the 40 members. Builder and society in collusion as secretary of society is builders employee and has encroached on common society area. So builder wants to retain land in his own name and deny conveyance deed to society. Secretary of society has formed a small cartel of individuals who have made individual sale deeds and is opposing conveyance process which was in progress for last 4 years. Three members went to district forum and filed complaint. Shockingly complaint dismissed and material evidence such as undertaking of builder and letter of society registrar (confirming that builder is obligated to do conveyance) is suppressed. State commission refusing to admit case on grounds that the ones who made individual sale deeds should have been made a party to the case although we have made the society a party to the case of which they are members. State commission order ( without admission of case) is awaited. What can be done. Please advise.