Renovation law

Hello, We had purchased a flat which is 3BHK and wished to get it renovated. In our plan, We feel kitchen is small, and hence we think of shifting the brick wall from 7 feet to 8 feet towards drawing room and another small modification to the brick wall of bathroom area, assuring no beam beneath it. When we approach society, they asked permission from certified structural engineer. Despite structural engineer's persmission, society has rejected our plea to proceed and they say that a rule was made, that no further modifications shall be allowed in the flat. I want to make a note that, in that society, many tenantable individuals, who owns their flats, have done lot of changes (eg. converting the whole kitchen to drawing room and shifting their kitchen to bathroom area). Also a bmc rule, Change in horizontal or vertical existing dimensions of the structure, kindly explain this please. Kindly, Help me understand the law and rules, for my permission and to make them realize for their injustice towards their rule. Thanking you, Regards, Sorabh Jain.