The real reason is actually quite simple.
If you maintain the machinery/factory/plant as it should be, it would cost, let's say R1 million a month.
However, (leaving aside the obligatory rampant theft and corruption in this instance,) if you let the system collapse, it will now cost say R30...
Definitely the Nokia ( I think the name was ) The E90 Communicator.
They were so far ahead with their technology before they unfortunately lost the plot.
As the old maxim says " Bullshite baffles Brains"
The banks are more than capable of instantaneous transfers, however that does not suit them.
Profits are far more important than customer satisfaction.
Oh, and the most ludicrous statement of all, " It takes longer if payment is made on a Friday...