Dear @Law101 ,
We are happy to assist you a integrating a Shopify subscription Application integrated with South African supported payment gateway.
my contact email is nipuna at oganro . com. Feel free to drop me an email for more details.
In the mean time, please see below payment gateway which support subscriptions/Direct Debit/Recharge for South Africa.
https://gocardless.com/faq/merchants/international-payments/