Sjoe. Cape Town charges R219.21 ex VAT, and everyone on the Home User Tariff pays that regardless of how much you use. What tariff you are on depends on the value of the home (mostly, there are some other factors probably not relevant here).
In exchange for the service charge, your <600kWh rate is R3.09/kWh. On the older domestic tariff, that had no service charge, it would be R3.51/kWh. The eagle eyed mathy people will note that the 42 cents difference, multiplied by 600 units, is about on the same ballpark. That is not by accident 