Society wants to stop dance classes after 10 years of allowing it.

We live in a housing society for the past 11 years in Goa. My daughter was taking dance classes where a teacher would come to our house teach. Slowly, few others joined and kids from the society too started coming in. This happens thrice a week and has been going on for the past 11 years and the society never objected about it. Please note that we don't take any space rental from the teacher since most of the kids are girls and are between the age of 5 and 12. The dance classes happen from 4pm to 6pm on friday and saturday and 9:30 am to 1pm on sundays. Recently, our new neighbour (bought the flat last year and live above us)started a petition to stop the dance classes. This said neighbour has been living in the same house for past few years but recently purchased the flat and became the owner. Last year this issue was closed down after numerous back and forth emails and it subsequently died down. Now again, a year later we have been asked to shut it down again. The problem is cited by only one member of the society, who lives ABOVE us. Our adjacent neighbours have no complains. The following things to note down: 1. The flat is owned by us. We are legal owners of our premises. 2. The sound is bare minimum. We have checked it using decibel measuring apps. And it obeys the sound regulations. 3. They had imposed security rules saying children should be dropped at the main gate and walk to our house. This has been the norm and irrespective of whether the watchman allows vehicles or not, the children still walk. 4. This is more like a charity that we are doing for the girls. And a lot of them have benefitted with a degree in Classical dance and has helped them with their careers and gaining a valuable skill set. 5. We have gone through a lot of mental stress due to this. The society has never objected to it for 10 years. The society member's kids too attend the classes. We need help in how can we shut this entire episode once and for all without shutting the dance classes. As to whatever I've read about other such cases that've happened where the court has ruled in favour of such practises since they don't violate the regulations of residential property. The classes take less than 20% of our entire property and is continuously inhabited by us and is used as a residence. We really want to serve them with a mental harassment case. It's been too much to handle. And our neighbour who has been the voice to this entire fiasco is been doing this for a personal grudge to the point that they purchased the property to make it possible to raise their voice. How can we stop this ordeal? Please help.