How can I activate blackberry messenger on blackberry 9930 in south africa

You first need to buy R60 airtime for the network you are using such as MTN, Vodacom, Cell C etc. That R60 will be the amount you need for (BIS) Blackberry Internet Service. You need BIS to enable BBM (Blackberry Messenger) to work. Once you have topped up your airtime with R60, you need to dial *141*11# which should bring up the option to activate BIS. Choose BIS and not any other option. BIS is usually option 1, but just make sure you select to activate BIS. Once BIS is activated then you can go onto BBM (Blackberry Messenger) and you should be able to send messages. You then have internet access as well. The great thing about the BIS is that it lasts for a month, without you needing to pay anything after the R60 to send as many messages as you like for free on BBM, plus you can use the internet on your phone as much as you like too! I am experiencing a problem getting BIS on my Blackberry Curve which I shall ask a question about on this site!! Good luck :)