IUA Failing to make payments

After days of sending mails up and down to IUA Business Solutions i have not received a call from them and they are doing everything in their power to now not make retrenchment cover payments but we paid them for this service for few years already. Each time they request additional documents even tho we already sent it to them, they are refusing that i speak to a manager also and say i am not permitted to talk to a manager. I am getting nowhere with them. I took retrenchment cover when i purchased a vehicle.