It sounds like you want to contact the Criminal Cashier's Office at the Nassau County District Court in Hempstead. The number is available online.
The return of bail does take some time. But you have been waiting too long. The first question for you to ask is whether the bail was exonerated. You should call the Nassau County Criminal Court Clerk and ask them if your bail was exonerated. If it has not been, then it will not be returned to you. Do not worry, if it has not been exonerated there is nothing you have to do to get it exonerated. Next contact the Department of Finance in Nassau County to get the status of the return of the bail.
You will need the docket number of your case and the receipt number on the bail receipt.