Exceptional bad service

And here the saga continue. My wife's phone is blocked again. After phone call after phone call we are now advised that her account is in arears with over R200. Where do you get from arears of R4 to overR200? We have paid every month!!! When you ask to cancel your contract you are friendly advised that you are welcome to phone the Retension Department!!!! Can you please cancel my wife's cell phone contract with immediate effect.