After placing an online order, one gets a tracking number from the vendor. However, if you have placed orders with more than one vendor, it's a bit of schlepp to track them all individually. I've found it easier to use just one website if I'm expecting multiple deliveries. However, I must point out that I have never been able to find info about parcels with Courier Guy - neither via this website nor via the link sent to me by the vendor.
http://trackmyparcel.co.za/
http://trackmyparcel.co.za/