Overcharge of non occupancy charge

Society is charging 10% of leave and licence agreement(RENT) as non occupancy charge. I discoverd that it should be charged as 10% of maintenace charge or service charge. I wrote a letter addressing the secretary/chairman in which I mentioned the law and requested them to charge as per bye laws. I wrote letter to the socity after receiving maintenance bill from tenant which was after 60 days. Current non occupancy charge levied is 12 times more then what it should be. Society replied to my letter that it was agreed by members present in AGM to charge 10% of leave and license agreement as non occupany charge and nobody opposed it and I shall be binding by this decision until next AGM. I didn't attend AGM. Out of 10 members(shop owners) only 2 were present in AGM. Shouldn't society office bearers abide by bye laws? Can society over look bye laws and pass their own rules? Does members absence in AGM doesn't give them right to protest later? If I had to take this legally what I should do. Matter pertaining to vasai-virar,Maharashtra. All help is deeply appreciated!