Failure to deliver by PAXI

2nd time sending parcels Pep Paxi where my parcels are delayed. The 1st it took 15 days and the receiver found the package not sealed(the plastic was literally opened) Now on the 10th of April, sent an item at Pep home iLangaP5755 and did the 3 to 5 days to P5740 in Centurion,it’s the 17th of April at 17h57,parcel not yet delivered. Tracked on the website,says failure to deliver,investigation underway.Called customer care and was informed that the courier went back with the parcel in the morning because they cannot find it on the system as a receiving store,how so?when I even received an sms stating destination?