Builder promised parking, but refusing it now. What to do ?

Sir, I am k.a from Hyderabad, Telangana, purchased a flat in apartment in 2015 november. I have given advance in october and done registration in march in 2016 at the time of purchasing and registration. The builder said I will be getting 70 sqfts of parking in the parking space but now due to the pillars the parking space is not sufficient for all 10 flats now he is converting the drive way in the parking to parking space and forcing me to take the chit in the parking considering the drive way as the parking I am not intrested to take the drive way as my parking if the chit comes for me. The builder also stays in the same apartment and he is not willing to take the drive way voulantarily himself and demanding to take the chits. According to me he promised a parking space in the proper parking space and now he is trying to adjust drive way as drive way. Now what should i do.