Study material not receive Post office/ UNISA

I have receive an sms from UNISA on the 17/08/18 that my study material was dispatched from them to Boksburg Post office a month ago till now I have not receive it. I went and check with Unisa and I was advice they have given the study material to the post office and I must check with the hub ( post office in Germiston), the hub ( post office in Germiston) advice me that the study material was delivered to Boksburg post office on the 3/09/18. today I call Boksburg post office to enquire and I was advice they have not receive the study and they only receive delivery @ 16:00 everyday. please assist ref : PP ********** 97ZA and DISP No: C27/2018-398P. My contact no: ********** 697