How to deal with builder delay and denial to maintain the property?

The flat was ready in 2018 in Pune but builder refused to repair the leakage in bedroom. Even after several emails there was no confirmation of repair & no proof was ever sent. Also in aapna aap i get calls asking for permission to enter in my flat which I haven't got possession. The property tax is not paid by builder & the electric charges are also not paid by builder. Now builder is asking for balance payment with delay charges. The builder is not ready to clear electric bills & property tax. Since the repair work was refused I had stopped the payment & till date there is no answer from builder for repair work. Builder refused to pay property tax & electric bills stating it's not their responsibility. Builder is stating first you take possession & then we will see. now after several emails the repair work is not done so can't I get the entire paid amount back with interest. Who pays property tax if possession is with builder?