Trending @Accenture; Serving notice period : Requesting early release

I am currently serving notice period and my project release date is end of august month and my LWD in organization is 12th oct officially but I am asking to release me 16 days prior becoz i even dont have dependency and getting released from project as well For the same my manager and supervisor both are ready but HR is not accepting it and saying that it needs business lead approval and bla bla Now again Hr said to my supervisor that they will have discussions and confirm Could some please suggest me how can I convince HR