House trespass

I bought a free hold property being a flat of superbuilt area of 876 sq feet in first floor of a G+3 storied residential and commercial apartment type stand alone building ( ground floor consisting of two commercial portions) from the father of the promoter / developer of the flat ; more or less one month ago , the one portion of the ground floor owned by the promoter gave on rent basis to some company namely macneill engineering ltd . using it as showroom to sell and repair electric totos . 2. As verbally reported by the company representative / employee , with the permission of the promoter , the company fixed their sign board ( weight around more or less 80 Kgs ) occupying almost half portion of the outer wall / front side of the balcony of my balcony and for fixing the sign board they drilled the said wall of the balcony and which caused crack on both the outer and insider wall of my balcony . 3. They have also been using the water from same water tank / pump motor meant only for residential flats of the appartment to wash their totos . 4. My repeated requests over phone to the said company representative and the promoter have failed and still they have remained reluctant to open the sign board from the area of my property . Request your precious advises for me