Monthly maintenance of 2 bhk apartment in chennai -reg

we've 144 flats (48- 2 bhk (985 q.ft), 48-2.5bhk (1313 & 1330 sq ft) & 48-3bhk (1481 sq.ft))in our apartment complex all developed by a single builder, subsequently taken over by the elected association. Maintenance during the first year was with the builder and he charged a flat rate of RS 2/sqft now after the association has taken over in 2015 there was a general body meeting followed by few rounds of meeting with the association office bearers. subsequently they maintenance charges were revised from per sq. ft basis to a hybrid system of fixed and variable charges as per which the maintenance got revised as Rs 1800 for 2 bhk, Rs 2000 for 2.5 bhk and Rs 2100 for 3 bhk. Now the previous association has demitted their office term and new association has taken over citing increase in maintenance cost tthey've proposed to revise per flat maintenance cost. Rs 2100- 2 bhk, Rs 2300-2.5bhk and Rs 2400-3bhk. Totally contravening the provisions of Tamilnadu Apartment ownership act regarding maintenance. Further the request made by the 2 bhk owners is challenged by the association as the same has to be proved in general meeting with 2/3 majority. MAy pls advise on how to proceed.