SA Post Office
Registered letter not delevered

I posted a package letter to my sister to the address: Ikanegeng Combined School, P O Box 40, Jacobsdal 8710. I posted this letter on 28 January 2014 at Bedworth Park, Vanderbijlpark post office, even today the letter has not yet arrived to her. The package contains very important documents that should have already reached her. The tracking number for the package is: RD422719245ZA. I would like to know what happened to the package.