Distressed platinum card holder

I've been trying to get hold of fnb since last month to change my debit order date because I'm starting a new job .I've been receiving poor service and I've reported this to fnb head quarters but I got no reply .im currently standing at fnb carnival mall waiting for their call center to pick since they said there's no way they can help me except this way.ive been wasting airtime trying to call their call centre but I can't get through. Tell me ..what should I do now because they can't debit their money this month it won't go through and I'll be sitting with unnecessary bank charges and penalties for something I've been trying to fix long time ago