The latest money making schemes with pre-paid electricity (Cape Town)

Yesterday evening I went to buy 20.00 Rand (ZAR) electricity pre-paid electricity for the Econometer, just to discover that I would have to pay an additional 3.95 Rand. It turns out, that the so-called "Free Minutes" are actually paid for throughout the rest of the month. There are three companies as far as I know that supply pre-paid electricity for the same devices. One of these three is using this system based on lies to make money, because people think they get free monthly electricity.