No over night delivery

I send a parcel at 8:30am from the Highveld, Centurion post office for overnight delivery to Cape Town on 02 July 2015. And when I checked status 03 July 2015 the parcel has not even left the Jhb central hub. I paid for overnight but now the parcel will only reach its destination in 4 days time. very bad unacceptable service.