Insane tarrifs

I don't live in the Geluksdal area, however I'm from there, and frequently visit my mother and grandmother. I realized recently that when they purchase electricity during the month the prices are different from the end of the month. For example if you buy electricity during the month for a R 100 you'll get about 19.2 units at most but if you buy electricity for the same amount at the end of the month it'll be about 60.2 units. I am utterly confused at this because people shouldn't be cheated this way of their money. On top of all the load shedding. They need to buy all their electricity at the end of the month or they don't get their money's worth. ITS NOT FAIR!!!