How is VAT calculated on imported goods?
VAT on imported goods is paid on the Added Tax Value (ATV) and this is determined as follows:Customs Value, plus any duty levied on the goods, plus 10 per cent of the Customs Value.

What is the R24 fee that the South Africa Post Office charges on postal items?
The CN22 code R24 charge is a Post Office Assessment Fee and not a SARS Customs charge. As per the Post Office website on page 18: