Parking issue in non gated areas built by DDA

Hi i have been living in DDA flats I am living in building A and the offender lives in building B , both buildings have a road in between and have their own separate garage(two wheelers only), own entrances and separate electric meters and water meters. The residents installed a steel gate to save space for parking and avoid the free flow of traffic . Though the road on which the gate is installed connect directly to main road and no permission was taken from MCD or DCP to install this gate its illegal. Problem : Though building B has enough space in its premise (areas not part of the road) where 6 cars can park at front and 3 cars can be parked at the back side of building , there is one guy who intentionally park his car in my building's premise. Due to structural constraints our building has only 4 car parking spots in the premise . Though there are 2 spots always available at front side of building B and 3 at back side of building B , this guy intentionally park 2 of his cars at spots present at the premise of building A where i live. Can you guide me how can i take this forward i am adding link to the image of locality for better understanding . https://ibb.co/SVbyPmq