Can my housing society deny me the use of my car parking

Dear Sir, I bought a resale flat in the year 2015. I have received a car parking allotment letter from the previous owner. However, the society is not accepting this letter. They are claiming that the same car parking allotment has 2 letters issued to different owners by the builders. The first letter was issued to another owner in the year 2000. The society was formed in the year 2005. My previous owner purchased the flat in the year 2006. The handover of the documents by the builder to the society was in the year 2007. In this letter it clearly says that the car parking is allotted to my previous owner. Kindly guide me Can society deny my right to enjoy car parking? Is a letter allotted by the builder after the formation of the society and before the handover of the documents considered valid?