Neighbor Building On Compound Wall

My neighbour has built his house on his compound wall before we bought this land, we have built our house at a 3 feet distance from the compound wall. Now he is further increasing the height of the building on the compound wall itself with his windows opening inside our area what can I do about it. They don't care whatever I say and keep continuing with their work. If I file a case will I have to go to the court regularly for the matter or the corporation will take care.