Settlement paid - unable to close my account

I am really upset with Game / RCS. I phoned on the 29.9.2015 and got a settlement amount of R37918.24 and paid it on the same day (proof was sent to confirm this). I sent a letter to close my account and still today they do not want to close my account as they say the person that calculated the amount did so in error. This is not my problem it is on the voice recorder. I kept on phoning to make sure my account is closed and they refuse to do so as they keep on saying I need to pay. This is not how it works. If this account is not closed in 5 days I will be taking the matter further and will be contacting the ombudsman. I am not playing with this anymore,