Reg. increase in super area by builder at time of possession

Booked flat in 2006 with Rs. 400000/- for super area of 1625 sq. ft @ 1625 per sq. ft. Allotment letter issued in May-2011.As per one of T&C of allotment if any variation in super area is done as per direction of DTCP then option was to be given to allottee to retain or cancel booking. 90% of amount paid upto Nov. 2011 & Seller buyer agreement signed in nov. 2011. One clause stated that area is tentative & can be enhanced by self or due to variation in lay out plan by DTCP. no information about change in area but in invoice/ state of A/c at time of offer in feb. 2012 increased area by 220 sq. ft. no details given even after sending 10 regd. letters. Started levying holding, refurbishment charges & threatened to cancel booking. possession not given . Case filed in consumer forum by me, where builder taking stand that as per agreement they can increase area. but my contention is that I was to be given option to retain or cancel the flat & also was to be given details of increase in area as how it increased , whether due to any variation in lay out plan by DTCP. No information . possession is being opposed by Builder & have added many charges. After paying full amount 6 years ago I am struggling to get the Flat . Pl. Long long dates are being given by court. Pl advise what should I do to get possession of Flat & whether I am liable to make payment for increased super area which they only mentioned in State of Account & no details given even till date except on a piece of paper not signed by them V.Kumar