301 Redirect
Search engines may think www.example.co.za and example.co.za are two different sites.You should set up a permanent redirect (technically called a 301 redirect) between these sites. Once you do that, you will get full search engine credit for your work on these sites.
In example.co.za html root folder create the following:
vi .htaccess
RewriteEngine on
rewritecond %{http_host} ^example.co.za [nc]
rewriterule ^(.*)$ http://www.example.co.za/$1 [r=301,nc]