Construction abandoned

I have purchased holiday home in murbad, kalyan the developer vishwamarut township, maru builder the builder was a old man died before completing the project he has 2 sons, who had not done anything about the property for almost 2 years they then handed the construction to "bio vishwas" which did construction for 6 months, then they also abandoned, they are asking for money back from those 2 sons, which they paid 1 crore advance before starting construction. now these 2 sons, have abandoned the project, nothing is going on since 1 year, and they dont plan to construct, they are looking for contractor, which they can handover the construction work, which they are not getting i have paid 671000, in 2011, but still nothing is happening, iam asking for money back, but they are saying that when the sell the project, they will pay me, but the project is difficult to sell, they are looking for buyers the previous contractor "bio vishwas" abandoned the project, becoz they were not able to do any sales my money is struck up, since the project is abandoned, in this case what is need to do should i approach local politician or police complaint or consumer case?