Bad service for a lack of better words

I have been battling with Cell C for over a year now. They never reply or respond to any inquiries yet every month they debit my account and every month I must reverse these unauthorised transactions. I have requested proof of installation and or proof of delivery for router I have never received. I have communications from the rep that assisted me in my moment of madness when I actually wanted to do business with Cell C. He confirmed that they have not completed the installation. Is there no person at Cell C with the authority's to respond to my queries?