This sounds like a very serious issue.
Your employer can be threatened with a complaint to the Department of Labour or even SARS directly as they are the ones who administer the UIF fund.
A labour inspector (appointed by the Department of Labour) is empower to make a compliance order that can be made an order of the Labour Court forcing an employer to comply with the terms of the Act.
My suggestion would be to approach the Deparment of Labour or even SARS themselves for the matter to be referred to a Labour Inspector.
KM, Labour Protect