Cell C cannot answer their phone

I am a fundraiser. I am trying to find the email address for the corporate social investment department for Cell C. I was given 4 different numbers to call and was given the supposed head office number by 2 different customer care employees. I called the number twice, the second time letting it ring 30 times. I am amazed that a major corporate company in South Africa like Cell C cannot answer their own phones. How do they treat their customers?