When receiving the error it could be that your IP address is on a blacklist or its not allowed to connect to server due to firewall restrictions.
Firstly, confirm your IP address at https://www.whatismyip.com/
You can verify whether the IP address is blacklisted by having it checked through websites such as MXToolbox.
The other alternative is that the IP is outside of South Africa or you're using a VPN and would be monitored more strictly.
Now check the IP country by looking at iplocation.net