Advise

I live in an apartment 202 since 20 years infact we are the first one to own a flat and get in to apartment. It’s been 20 years and there is no improvement or progress of the apartment we keep sharing amount for same things to be repaired or fix any issue. The 3rd floor flats seems to be leaking of water from terrace which has water tanks. They claim that all the flats has to share to repair and fix the issue but then when 2nd floor flats has any leakages non of the flats would be ready to share amount for the same. As we are in the middle we have to fix our own things and common areas always we have to share which is going out if head now. This time we refused to share the amount for those slab work which is a leakage for the 3rd floor. Now the secretary says the flats who r not ready to share amount cannot use terrace and it will be locked which is open harassment and also blackmailing, forcing to pay for those repairs. No one has any right to force someone to share amount when they are not interested or not want to share when it has not taken the equal call for 2nd floor aswell. Kindly suggest how to proceed in legal way.