SA Postal service is terrible

My item arrived in the country on the 18th June 2019 it was then at customs for 10 day, the next update was that the package was leaving customs on the 28th of June 2019 I have been waiting for the package to arrive, I have contacted the customer care line and all the other numbers no one can tell me anything about where my package is, today I check my tracking information an there is a new update saying the item cannot be delivered and will be returned!! this was on the 10th August 2019. I have not received any notification to collect my package, I do not know where it is, how can it be sent back when I haven't been informed to collect it an no attempt has been made to inform me. after spending 30 mins on hold with customer care waiting for an agent to answer I get told they don't have a south African tracking number for my parcel and it looks like its still at OR Tambo!! HOW IS IT POSSIBLE FOR MY PACKAGE TO GET SENT BACK WHEN IT HASNT EVEN BEEN PROCESSED!! PLEASE HELP ME!!! the tracking number is RU***NL