SANDF chief Lieutenant-General Vusumuzi Masondo needed to explain how it was possible that a decision to dismiss soldiers was taken without first subjecting them to disciplinary processes, the union's national secretary Pikkie Greeff said.
The defence force's spokesperson Xolani Mabanga could not immediately confirm Sandu's statement.
"I cannot confirm that they were dismissed, however what I do know is that we are in the process of taking disciplinary measures against those who disobeyed the instructions to return to their home bases," Mabanga said.
In August, the Supreme Court of Appeal found the dismissal, without a hearing, of 650 soldiers involved in an illegal march on the Union Buildings in 2009 was unlawful.
Only 296 of those charged had been subjected to a probe, in Mtubatuba, KwaZulu-Natal. Due to a lack of evidence against them they were recalled to duty and their special leave was cancelled.
Greef said the balance of members on special leave were not charged and, until their dismissal on Friday, remained at home.
"The question arises as to why the special leave of the members at the KwaZulu-Natal probe was revoked but not that of the remaining affected members."
Greeff said hundreds of soldiers reported to their bases this week to enquire about the cancellation of their special leave, but had been told to stay at home.
"If the basis for such dismissals is the failure of affected members to report for duty, then Sandu challenges Masondo to produce evidence of any such recalls," he said.
"If such proof exists, he must explain why the members were not afforded an opportunity in due process of law to be notified of their recall and a chance to explain their alleged failure to return to duty."
Mabanga conceded that on August 20, the Supreme Court of Appeal found the SANDF had been unfair by not following correct dismissal processes.
However, in the judgment, the court stated that the SANDF had the right to maintain and manage a disciplined military force as required by the Constitution.
"As a result, the SANDF issued instructions to those soldiers to report to their home units for arraignment. Some responded positively to that instruction and some deliberately ignored it," Mabanga said.
"If they disobeyed the instruction, according to the policies and administrative rules, they would then face disciplinary measures, one of which could be discharge."
While Sandu maintained its members did not receive instructions to report to their home bases, Mabanga said the SANDF was mindful of individuals and organisations misleading people for their personal gain. – Sapa