Telkom Internet because the total cost (bundle of all services) is cheaper than using a different ISP. Previously I used Afrihost when they were cheaper, and before that Telkom again because they were cheaper. I review my ISP every few years when I find out about better deals.
Have always been with Telkom and have generally positive interactions with them. Also, I pay the monthly bill via my work credit card which is easier with Telkom.
Screamer because they have their own network so no issues with support and excuses about someone elses network giving problems and their 20 Mb uncapped is the most price competitive in the market
Axxess because they offer good value for money and month to month instead of a contract. Also they've been ISP of the year several years now and I've always enjoyed good service from them for years now
Webafrica - moved to them from Afrihost when Afrihost support was non-existent (hosting server was down for 3 days before they admitted it was really down!).
Unfortunately Webafrica seems to be taking lessons from Afrihost - I'm on day 8 of a support ticket, with 3 escalations, and have not heard a single word from them......
Started out with VOX because of their big ADSL Fat pipe discounts, and it was easy to shift to a fiber package from then on. Always had good support from them too so I've never felt a need to change ISP's.
Vox Fibre - 100/50 mb/s (purely for speed and latency), I chose 600GB cap (not available anymore) because of the 6 months roll over, end up collecting about 4TB of unshaped data due to this. which is better than uncapped as you get throttled usually after 2TB. So if the time comes when I need TB's I've got it. Cost is R1200 p/m. Been with Vox for 15 years, rarely ever had an issue even on my previous ADSL line. Vumatel are the only ones giving problems consistently.
We use Home Connect. At the time of signing up they were the cheapest for an uncapped 50/50 line month to month contract. Even though we're on a month to month they have kept the fee the same since we took it on.