Service to the port 43 WHOIS service for .ORG.ZA domains has been restored again.
Original report on 3 May
The WHOIS service by ZA Central Registry is not responding to queries for .ORG.ZA domains. As a result, all lookups for .ORG.ZA domains on our website will fail suggesting that the domains are already registered. We have opened a support ticket with ZA Central Registry.