Vadacom poor servicing and unprofessional behavior

I settled and canceled a vodacom data subscription contract because of their poor service in respect of collections. They listed my account with a credit bureau with arrears i did not understand. They costed me alsp when I bought a car - I got charged higher a interest rate because of their actions. Even to date after several efforts trying to remove it and reverse the impact- it is still adversely impacting my finances because it doesn't get updated yet I settled long time ago.