Boundary wall demolition by my neighbour

Neighbour = He Neighbour + Building contract company = They My compound/boundary wall is about 50 years old. My neighbour (owner of the adjacent plot) had built a boundary/compound wall plastered to mine about 30+ years back. He is now trying to demolish his boundary/compound wall, without my consent. He says he wants to build a new boundary/compound wall as he has constructed a complex to be let out for offices. If he attempts to demolish his compound wall, just the impact itself will bring down my boundary/compound wall. The construction contractor or the neighbour didn't communicate to me that they are going to demolish. By chance, this morning, i had heard/seen him breaking the boundary/compound wall. I objected and made them stop work. During the construction work, there were incidents of throwing human waste and other things into my property. In his office complex construction, he has built several windows overseeing my property. He has not sought permission from my side for the windows they have constructed. my house developed severe cracks on the walls as they bulldozed the existing structure and during plastering work, my recently painted house (outer walls) is now full of cement. Should i complain to the municipality /police if continues demolishing the compound wall ? What should be done within the legal extent. Please advice me accordingly.