Coca cola branches

They don't answer their phones at wadeville, Bedfordview and midrand. I drove to the wadeville branch just to be told that they have no telephone numbers....as per the security guards. I need to speak to the buyer but I have no way of getting hold of her. This is the 21st century and trying to contact one of the biggest companies in the world who have no details that work but theres a number on their website. How does that work? This is ridiculous!