Why does CellC have a contact us on their web page

I contacted CellC via their web page but got no response. Why do they have a contact us if they don't respond? My March 2016 account suddenly has a new charge under call charges! This is a charge for smart data internet for R 23.46, and then to add insult to injury, they tack on R 1.50 for remaining charges. I never agreed to anything called smart data internet, and what is a remaining charge? When will CellC stop trying to cheat their customers?