Builder Construction Delay

We had booked an under construction property in 2009 (flat in multi- storey building), its been almost 7 years and the builder has not handed over the flat. The current status the flat is almost ready- without electricity connection and plumbing. Its a multi-storey building, and only one lift is provided with manual operation, other lift only the trench is there, no lift. There are few people in building who have taken the keys and done grah pravesam. But the flat the builder has not provided completion certificate. We have been persuing the builder for very long time, and every time he has given us revised dates. We have lost our patience with the builder and have currently formed a buyers association with about 100 + people in the complex. Most flats in the complex are in varying stage on construction- such as flooring not completed, plastering not done etc. All the floors are constructed. Builder is not even talking about the common ammenties such as garden, multi purpose hall, gym etc. The builder has already few cases against him for tax evasion ( he was put in custody for the same, out on bail) and other cases. There are lot of creditors who are behind him. His other properties are also stalled Please suggest how do we take this forward? We would want to see returns on our hard earned money invested and finally move into a self possessed home. There are few things which we see as risks and hence have not taken a legal approach yet. 1. Builder putting the project on hold since we have gone legal 2. Legal verdict / consumer court verdict taking a long time - serveral years more to our agony. 3. Most legal battles go towards compensation - but we want our flats first and then compensation for all the mental agony we have gone though these years. 4. Legal charges would be heavy Kindly suggest the approach we should take to get a quick resolution.