Cell C is a ****

Having cell phone contract with cell C is a nightmare I have a contract with cell C and I'm paying my account every month,but I will receive a call and smses stating that I did not pay my account and the worse part is that they are even updating on my credit profile,this thing is affecting my credit profile.The staff is not professional at all ,I don't if they are hiring people who doesn't have matric or what.Please assist I need to escalate this or terminate this contract if possible.