Building maintenance issues

Hi Sir/Madam I have following situation, please suggest. - Housing flat project located in Bangalore, builder promised completion in March 2019 - I shifted to the flat in Sept 2019 and its going to be 2 years now - However, it has still not 100% complete, gym and access road is pending - Last lift completed 2 weeks ago. - Builder never made any association - Certailn group of people took over and made an assiciation without voting - Now there is a seepage issues from the roof which is a building issue - it involves high maintenance amout to fix that issue - Since the builder has not done any handover, he should take care of it - builder denied to take care of it and association pushing the top floor owners to fix that themselves - Association has not been giving any recipt of payment done to them - They have recently created an account after people denied paying to personal accounts - The association have been biased and not helping to resolve the issue and so do builder Please suggest. Thank you KB