unilateral termination of contract

I took out contracts with Telkom for cell phone lines, Telkom than terminated the contract alleging that I came in the shop to terminate, I asked them for prove of termination, no one could assist even the lady that assisted me in their menlyn branch, was surprised. later seeing that they don't have a leg to stand on than they said it was because I did not make payments which I disputed, they however continued deducting monies from my account, until last year July when they deducted more than R9000.00 , that was the final straw and I enquired and they could not even explain what the amount was for, so I started reversing all the deductions they where making, I said to them since the contract has been terminated what is it that I owe them, till today they have never supp**** me with a statement to explain what I owe them, but they keep wanting to deduct monies from my account and I keep reversing these, Telkom must come clean and advise what I owe them or I will have no option but to seek legal advise and an interdict to stop them from deducting money from my account as it puts me in a bad light with my bank