[Resolved]  Cooperative Housing Society — Seepage problem in flat

Recently, I observed that a new seepage has developed in the other bathroom ceiling, which probably is attributed to a leak somewhere on the floor in the flat above. It is still not 3 years from the date I took possession of the flat from the builder.Since it is an issue involving both the flat above & my flat, I need co-operation from the person staying above my flat to get this issue sorted out & also, the society may not be concerned with this issue. In case, the person staying above does not co-operate, please can you let me know what is the way out.