Case to be filed against builder for cheating

I have purchased flat in Savannah society. Constructed by Bhandari associates located in Wagholi. Builder has changed the plan which was shown to us without any prior intimation, also as per him he has sold the FSI of societies internal road to PMRDA and saying that it's a public road now. He has sold the aminity space to one of the school and all heavy construction vehicles are moving from our internal road which is very unsafe for our children. The society is formed in year 2015 and till date builder has not executed the conveyance deed. Need advise on which points a strong case can be filed against the builder.