Priority letter still hasn't arrived even after 2 months

I sent a Priority Letter (with the tracking number RI ********** 19ZA) from Germany to South Africa. The employee at the German Post Office told me, that it just takes 8 to 11 days until the letter arrives. Especially because it is "just" a Priority Letter and not a parcel.

Well, the letter arrived in South Africa after 7 days, but it still hasn't arrived at its destination.

Since two weeks the letter is stuck at the JHB INT MAIL CENTRE (HUB). My friend waits for this letter since almost 2 months. I even sent four messages and still don't get any response from the South African Post Office.

The service is really poor. They could atleast answer the messages.