Severe seepage not repaired for 2 years

I had severe seepage in flat from beginning and the developer was instructed by me at the time of purchase that I will take possession only when it is repaired. Maintenance staff of ARG Developers is doing some cosmetic repairs by applying white cement on tiles for last two years and asking me to wait for seepage to dry. Seepage is still there in flat. ARG Developers Pvt. Ltd. has not done repair of pipe which requires breaking of tiles even once. There is fungus growing on walls and my phones to maintenance are going unanswered as they pretend that they can cant hear me even though I am talking on intercom.