Delay in providing amenities promised by builder

I am the owner of a flat in an apartment complex consisting of 64 flats.I bought the current flat as a resale from the first owner. The builder had appardently handed over the flats to the owners in 2014 without getting KWA water connection by promising to get it done with in a few months.He also collected a corpus fund for water connection, Electricity connection & maintenance fee from all owners.Even till date ,water connection has not been got and majority of our maintenance goes towards purchasing tanker water .The builder maintained the apartment 1 year.The STP broke down with in 6 months & builder didnt not repair it.Now we have as adhoc association to manage day today affairs but it is not registered yet.The Fire department found flaws with fire safety measures and asked the builder to correct them but nothing has been done.Also ,he has not handed over the corpus fund to association Whenever we ask the builder about these issues, he assures us speedy action but nothing is done.How can we tackle this builder now?