Complain about Cosmo city branch

I've a very concerning problem about the owner (Mr Naidoo) of the branch in Cosmo City city. He employed my wife in his branch from December 2017 and didn't give her any contract of employment. Because she was desperate for an employment, she didn't mind working without it.

On a Monday (24th September 2018) she requested Mr Naidoo a week off (from 28th September to 4th October) since we had plans for her birthday on the 2nd October. Mr Naidoo agreed and gave her the go ahead and we continued with the plans of booking the the vacation. On Thursday the 27th September, he said she can't go on leave anymore because he believed the store was going to be busy over the weekend and doesn't care whether the bookings/plans are made or not.

Since the plans were already made and paid for, we continued. On the 5th when she returned back to work, she was dismissed and even told since she doesn't have a contract, she is not owed anything she can just leave. That I know and understand that she couldn't get anything.

My question to Postnet is: how are the employees protected? Does Postnet follow the Labour regulations as per registering its employees with Labour? How does Postnet make sure the employees at the branches are given the contracts and registered with UIF? I believe and hope Postnet as a brand will have a proper way to resolve this matter.

NB: I sent the above message to Postnet call center on the 6th October and to date no reply was received hence I'm trying another way of sending my message.