Builder not providing parking place can we take action

A year back I bought a flat in a small apartment which has 8 flats. (4 floors, 2 flats each floor). There is no permission for 4th floor; and only 6 parking lots which are spacious and other two are congested. Builder did not allot the parking space intentionally until all the flats are sold. Finally, he allotted parking without any basis and two congested parking lots were allotted to individuals who have come first and have permission. Now they are not accepting the allotment and blocking the way. We have a registered flat owners association. Please let me know how we can proceed further.