Did not Receive my parcel

I have shipped a parcel using SAPO, the parcel has been received at the Joburg mail centre but it never got to my post office. I have contacted customer service so many times and they advised me that my parcel was send to Midrand post office. I went there so many times and they could not find it. when I track it the parcel is still showing that it is at JHB mail centre... I tried to lay complains with customer service with no help. Debbie and Eugen Kekane from customer service were not helpful at all. they kept telling me that my parcel was sent to Midrand even if I told them it was not there. I need the percel and I feel like this is really bad coz they cannot tell me where exactly is my parcel at.