Builders are lacking in due diligence

Hello Sir, I am Sunil, I have purchased a 1 bhk flat at Badlapur, Dist - Thane 2 years back. It is a ground+4 floor standalone building. There are several clause mentioned in the agreement and builders (3 partners) have promised us that it will get completed within time frame. Whenever we ask anyone of them they simply pass the ball in another builder's court. We all are fighting with builders since last 2 years to resolve issues and they not responding us. There are several quality issues like 1. Wiring in homes and building premises, 2. Severe wall leakages, 3. Society walls have not painted after raising it's height. 4. There are 2 water lines promised but only one provided and 2nd one given now without having proper sanction from water supply. 5. Society is not yet registered after submission of all necessary documents May I seek your expert advise to get these things done from builders. We also thought of initiate complaint with consumer forum, but we are lacking guidance and expertise to deal with such things. Please help me.