Cell C Continue to Rip their Customers

Once again I find myself writing yet another complain to Cell C about incorrect billing on my account 3 months in a row. <br> I really don't know what to do now with this company.<br> <br> Anyone reading this report, kindly advise what legal steps I Can take against cell c for their continued recklessness.<br> <br> I have a copy of a contract stating that my Post Data contract for 500mb day and 500 mb night data on the Huawei mate 7 gold cell phone is R389pm. why I'm I billed R670pm consistently?