increase in super area after booking without doing any extra civil work

Location/place: ebony greens crescent park -nh 24 gaziabad

Name of company/service: bvil

same thing happened with me.Without increase in room ares lobby area,toilet area, How they can increase super area without doing any extra civil work. can any body form sare saamag explain this. at the time of booking sare saamg used to tell super area is 950 sqft for 2bhk, 1150 sqft for 3bhk. after booking same area becomes 1033 sqft for 2bhk and 1244.42 sqft for 3bhk. How this is happening. this is policy for direct cheating.
correct Calculation of super area at time booking should have been done by sare saamg. Now tell me for which fault customer has to pay more due to increase in super area declared by SARE SAAMAG. Increase in super area should be approved by any third party agency or govt. agency first. then Sare saamag can claim to customer. am i writing wrong? change in area before and after booking should be clearly mentioned and approved by any third party agency or govt. agency
Please revert me if i am wrong.