Cheated by builder-Siddha Town

hi i have purchased one flat at Siddha town, Rajarhat, Kolkata. (1) They have charged Rs.250000 For car parking as right to park but as per West Bengal apartment owners act 1972, Carparking are part of common area. So when i have already paid for such area in super built up area whether such charges are legal. In 2010 supreme court made a judgment where they told car parking either open or closed cannot be sold. (2) They have charged service tax and stamp duty also. Whether it is legal? (3) As per agreement possession means House in bare condition and car parking. So can i claim interest from them as completion of possession not yet done. Also whether it wave my liability to pay maintenance charges as it ll be levied after possession(as per agreement). (4) As per agreement to sale they have mentioned banquet hall as a part of common area but while registering the same they secretly changed the terms and mentioned that banquet halls can be given to any one. They have not given any time to read the conveyance. in their agreement they mentioned arbitration clause so can we go to consumer court as it is clear that their intentions are to make illegal sale in the veil of agreement. Please help me in above mentioned points and guide me how to proceed a copy of agreement can be downloaded from https://www.siddhatown.com/rajarhat/downloads/SiddhaTown_AgreementForSale_Cluster4.zip thanks indeed arindam 7890400605