SA Post Office
My parcel is still sitting at customs after a week

I sent my wife and son a package from the US with a few little gifts for them. I traced it and it arrived in sa post office customs on the 4th of march and is still there today the 12th of march. My question is why is it still there after a week and when will it be delivered? It was sent to moreleta park Pretoria. I have a track and trace number.