It's not, it's a Dutch company
> Voys Telecom SA (Pty) Ltd A company with limited liability duly incorporated in terms of the Companies Act of South Africa, 71 of 2008, with registration number: 2013/114285/07, hereinafter referred to as “the Service Provider”;
As far as I can tell though each different country office operates largely independently, almost as a franchise. So it might still be that the South African branch, with a registered local entity and no EU-based customers is more focused on POPI than the GDPR.