F4 - My priority date is current but i didn't recieve interview letter.

[MohandGamal]

Hi Everyone , F4 Category

My Priority date is 20sep04 and it's current now but i didn't receive anything when i called nvc they said no visa available did anyone have same problem or know what is going on because there is many people got the interview after my priority and before but i didn't get it what is the problem ??????