Horrible service from sa post office

I have been waiting for a parcel since it was held at jhb international mall centre since 20. 03.20, nobody ever picks up the call center number, no update on my tracking number over a 100 rand on airtime to try to get assistance this service is pathetic, what am I supposed to do after I have paid for something but even my tracking number doesn't help me, I don't know what's happening and there is nobody to speak to telephonically, they don't even respond to emails I'm sending, so what am I supposed to do, I hope this is escalated to the highest person in charge.

Wendy Searle