can car parks of different sizes be sold for the same price

I have purchased a flat in chennai. Of the 4 different sizes of flat in our apartment mine is the 2nd biggest. the builder had an agreement with the buyers of selling car park for 1.5 lakhs in stilt area. On the plan they had shown the parking places with the flat numbers. It was only after completion of the apartment the size of each car park was known. The front and back portions of car parks are longer and broad but the side parks are of different sizes. 2 car parks on the sides are so wide that they can park two cars and the other 3 carparks can park 1car and a bike. But the rest of the 2 car parks can only park one car with half roof on top. the other half is ots. But the builder has collected the same amount for all. Due to ots the pigeons keep flying up and down and so i am not able to leave the car without cover for even one minute. My car cover is spoilt with full of pigeons droppings. And apart from this the old flat owners who sold their flats to builder have not paid for their car parks which are longer and wider the front and back car parks. out of 32 flats the corner front and back portions of flat on both A and B BLOCKS was sold by the builder and the rest for old flat owners. But the builders portion of flats that were sold for the new buyers are bigger in size, by one extra balcony. My question is can different sizes of car parks be sold for the same price. And the old flat owners have not paid for their parking area. My park has only half roof and the other half is ots. After paying 1.5 lakhs i am not able to park even one car without cover. what can I do. Please suggest me whether I can take legal action on the builder.