Trying to cancel mobile data account for 3 months

I went to Telkom Direct Kimberley in December 2015, they calculated the penalties that I will pay if I cancel my account early and I agreed to the amount. I Filled in the form and Telkom direct said they will fax it through and it will probably take a month to cancel the account. I deposited money into my telkom mobile account in december 2015 to cancel this 2,5gb data account, so my account is in credit for almost 3 months now and I keep following up on when this account will be cancelled and the call center agents keeps on sending emails to the cancellation department but nothing happens.