Seepage issue from upper floor

Hi, My flat is vacant from November 2023 due to seepage issue from upper floor. I did follow up multiple times with owner above and he was reluctant to share fixing cost. I did notice to society committee and then he started talking positive to fix it and sharing cost. After lot of follow ups, he tried to fix it through injection grouting but it didn't work. Now this need to be fixed by breaking and redoing of bathroom. He is not denying to fix it but taking months and month at every step. Society committee also not making effort to make it quick. I have already lost 8 months of rental income( approx 2 lacs) till now and I have been given another month promise that it will be fixed in July. In the past I also get it fixed thrice from paying from own pocket. Owner above didn't share cost in previous occasions. What should I do? should I sent legal notice to owner above to recover my rental losses and to society committee to waive off my maintenance charges for above mentioned period? Thanks Manoj - [deleted]