More precisely it is not vat/tax but conversion rates and or other fees. Even though they charge us in "zar" it is still foreign currency, conversion and "effort" applies. That is why you pay the added 2-5% which normally was done by the banks themselves.
ps. vat is not 2-5% nor is tax. please update loops. see #19
Surely that should have already been taken care of by the banks buy/sell rate for the currency in question?