Twenty-eight female guards were unfairly dismissed by a security company because the client‚ Metrora.
Telkom could still face a R5billion fine for anti-competitive behaviour, despite a High Court ruling in the operator's favour last week.
The court ruled on Friday that the Competition Commission could not refer a complaint against Telkom to the Competition Tribunal.
The commission has vowed to continue its pursuit of Telkom even if an appeal application to the High Court is unsuccessful.
Thulani Kunene, head of the enforcement and exemptions division at the commission, said yesterday: "We will go back and investigate the matter in a manner that satisfies the courts."
The commission's referral was blocked on the grounds that it was made out of time.
The commission also made the blunder of not consulting the Independent Communications Authority of South Africa (Icasa) on the issue.
Internet service providers have accused Telkom of charging them more for bandwidth than it charged its own Internet division, and refusing to supply some service providers any bandwidth at all.
Two months ago Telkom filed a lawsuit against the competition commission with the High Court claiming that the commission had no jurisdiction to prosecute the state-owned telecommunications monopoly over competition matters.