Issue with the Parking space

In my Society there are six buildings in line with no gap between the buildings. Each building shares a common wall. Ground floor is meant for parking the vehicles. Also, there is some parking space provided by the builder at the backside of the building’s. Since there is no space between two building’s residents must walk through the parking space of the ground floor. Now the issue is that, one of the flat owners owns a double car parking & has two cars, two motor cycles which are in use & one scrapped M80 & one scrapped Bajaj scooter. This person is parking his scrapped vehicles in such a way that it obstructs the way to commute to the back side of the building. Upon requesting him to remove these vehicles he is arguing that, he has paid the builder for the same & he can block the way also as his parked vehicle get scratched by the commutators. I believe that the parking space though it is allotted by the builder to a resident still treated as a common area. Please provide your guidance.