Vastu Vihar — A third class builder

I had booked a bunglow in Vastu vihar, Darbhanga phase -1 on 13.04.2015 after paying Rs.99, 329/- and after 2 months they have told me that they cant give me ant unit in this project but they have suggested me to opt any other bunglow in their new project pase-2 in Drabhanga itself and when i have visited the site i found that the project was about 15 km away from Darbhanga city .After my refusal, they have told me to wait for their new upcoming Project -phase -3 at Darbhanga Sonki road .
Finally they have done the Bhoomi Poojan of Vastu Vihar Phase -3 Darbhanga project on 11.08.2015 and asked me to pay Rs.11, 50, 434 (i.e 30% of the cost of the flat) on the date of booking itself however for other people (for new Customer) booking amount was fixed only rs.25000/-only .
Since I was in the trap of the builder I had no option but to pay the remaining amount(Rs.11, 50, 434) to make it 30 % cost of the flat on 11.08.2015 and they have allotted me a Yamuna Big Unit according to my choice and assured me that Registration will be done immediately.
But it is surprising that till date 14.02.2017 even after laps of approx 18 month they have not registered the unit in my name . Now they have changed the Master plan of project and insisting me to change the Unit as per their own Choice /convenianc and their benefit. Inspite of repeated reminder request, organisation is not doing the needful for registration of my allotted Unit no-Y-11 (Vatu Vihar, Phase –III of Darbhanga.

.It is also very important to mention that so far they have not started the work of the project.They have constructed only boundry wall and one project office and remaining land is with full of crop and water.