possession not get

Sir, I had booked a flat in November 2014 with one lac rupees.on 2 Feb 2015 , five lac paid(total 6 lac- more than 20% of total amount).My possession date was 31 Dec'2016. Owner aggremented in August 2015.During loan approval I found that land was not 'Vastu' Showing as 'Karkhana'.I asked the owner for this. He convensed me very soon it will converted.municipalty corporation just not being updated.So I have not give him next payment as my sense not demand by owner .when I had booked the flat structure was completed.After four years lapsed only wall and its plaster completed with wooden door frame also. wooden door with inferior quality. Also land not updated /converted yet which are showing online.Sir , what should I do? If I demand to refund the whole money what I get or claim as the law of west Bengal industry regulatory act?