Make sure that you top up more than R59.00 prepaid airtime.
MTN:
Dial *141*11# and press the call button.
Vodacom:
Either SMS the word BlackBerry to 100 or,
Dial *111#
Choose option 2 , “Bundle Purchase“
Choose option 4, “BlackBerry Purchase“
Then choose between a monthly subscription or a once-off
Confirm the purchase
You will then receive an SMS confirmation.
Once you receive it, you may want to do a battery pull for a couple of minutes and then replace it.
Once you see EDGE or 3G signal all in caps BIS is activated.
This is a thirty day thing, so you will have to recharge eg from 15 to 15 of following month.