Baggage not allowed on the return flight

It’s the worst airline that I have flown in the past few years. Every time I fly to Cape Town there’s no issue. On the return they don’t allow the same baggage back what I have arrived with. The only thing that the Flysafair staff and the manager says ( sorry we can’t allow it and thats it.) And there’s no plan that they can make. And this is now the second time.