My family lives on the top floor, and the roof leaks. Now there is no property in the community, and the after-sales service of the sales office does not matter. What should I do and who should I call

My family lives on the top floor, and the roof leaks. Now there is no property in the community, and the after-sales service of the sales office does not matter. What should I do and who should I call? Waterproof five-year warranty, the warranty period is the responsibility of the developer, do not handle complaints to the local quality supervision department, and then do not go to court. It's overdue, because it's a public part, and the maintenance cost should be shared upstairs and downstairs. Provide more information technically, and provide professional technical consultation on waterproof and leakage repair of concrete for free, so as to avoid the troubles of repairing today, leaking tomorrow, repairing every year and leaking every year.