change your server to durban quickly...run a test just want to check something...please
If you use the unrestricted APN it might give you an IP from another region causing the routing to be bad for example you can be in PTA and get an IP located in CPT and then your traffic will go from PTA > JHB > CPT > JHB or you could get a Durban IP and routed there.
A trace route will confirm this.






