Stahl cranes company is a no pay for work completed

This company does not pay their suppliers. Specifically at the Limpopo Platinum Mine site. Monies are outstanding for 90 days and their worker on site said Head Officr decdes who they want to pay and when they will pay. This is very unprofessional. They requested Load Testing of the lifting equipment at the Ivan Plat site, it was done 1st week of December and now they are just not paying.