Help getting started with Roku devices, including setup, connecting your device to your TV, linking a Roku device to your account at my.roku.com/link, adding channels, subscribing to services, and more.
Country matters a lot. While a Roku will technically work anywhere, it's not supported in South Africa and many channels/apps would not be available. I searched the channel store for DSTV and nothing came up. It would be up to them to create a Roku channel/app.