Apartment maintenance by sq ft — can a group of owners challenge it? chances, time, cost? (kerala)

We are a group of around 10 owners (3BHK and 2BHK flats) in a 76-unit apartment in Kozhikode. The Owners’ Association is registered under the Kerala Societies Registration Act, 2025. Flat composition (76 units): 2BHK — 50 flats (66%), 3BHK — 18 flats (24%), 1.5BHK — 8 flats (10%). The maintenance issue: Maintenance is charged purely by super built-up area (₹/sq ft), and the committee has just raised it from ₹3 to ₹4/sq ft (33% increase). From the association’s own accounts, about 80% of the expenses are common costs (security, housekeeping, lift, common electricity, STP) that every flat uses equally, regardless of size. So larger (3BHK) flats heavily subsidise the smaller ones. We have asked for a hybrid/equal-share method (common costs shared equally, structural costs by area). The committee refuses, citing the sale deed’s “proportionate share/UDS” and Section 10 of the Kerala Apartment Ownership Act, 1983. The bye-laws themselves fix no method. The representation problem: Because 2BHK flats are the majority (66%), the committee is dominated by 2BHK members, and whenever anything is put to a vote, the 2BHK bloc votes together and the minority (3BHK/1.5BHK owners) is always outvoted. So there is no realistic way to get a fairer method adopted through internal voting — the majority will always protect the area-based system that benefits them. Our questions (a group of ~20 owners prepared to file jointly): Is there a realistic probability of winning a case to require a fairer (hybrid/equal) method for common expenses, or to roll back the ₹4 hike — given that the minority can never win an internal vote? Which forum — Registrar of Societies, Consumer forum, or civil court? How long would it realistically take to a result? Approximate cost, and roughly what each owner would bear if ~10 of us share it? Does it matter whether a registered Deed of Declaration under the KAOA 1983 exists for our building?