Lost Parcel SA Post Office

I received an SMS from the SA Post Office regarding collection of my parcel, when I went to the Halfway House Post Office in Midrand my parcel was nowhere to be found. I was told that they will look for it and get back to me. Its been a week and no feedback has been received.I sent sent them an email regarding the matter and havent recieved any reply from them. I tried calling the Customer Service multiple times but no answer after 10 minutes. I called the head office and was given a new number of the customer center and still no answer from the new number. When I track my parcel it says it was returned to the JHB INTG MAIL CENTRE.