Telkom Billing an account that doesn't exist

I opened an account in 2011 with Telkom mobile (8ta) and it expired in 2013 September. Telkom reopened it on 2013-10-28 without my consent and started debiting my account. I went to their offices to complain and was advised to fill in a form to confirm cancellation even though there was no contract anymore. All said and done, I realized last week that Telkom is still debiting my account regardless of the formal cancellation, meaning they have been taking my money for 26 months without my knowledge. It was difficult to notice because they combined it with other accounts I have with them. Worse of all, when I inquire, they deny that I ever cancelled the contract, not considering that I am in possession of a copy of the cancellation letter. I have never used the number since the contract expired.<br> When I sought advice, they apologized and told me that they cannot give me my money back, but can only compensate me with airtime, something I disagree with in the strongest of terms. They debited money not airtime on my account. They cannot forcefully sell me something I do not need.<br> I just need my money back for the 26 month period or more if they still take time to resolve this.