Tracking System Down Since Oct 11, 2012

I had a confirmation email of a package shipped on Oct. 11, 2012. Trying to track my package which I paid for 2-day delivery, was supposed to arrive Saturday Oct. 13, 2012, and haven't recieved it. I have the tracking number, but ever since Thursday, every time I put the number in (copy and paste, so I know the number is correct), I get a NOT AVAILABLE message.