******* deductions on my bank account done by Telkom

I had a cellphone contract and a fibre line with Telkom. After the contract expired I closed the account in January and since then now June month they *****elent still deduct money from my bank account. Every time I phone with a reference number they say it is the last payment but the following month the debit order goes through with an increase amount. This is *******. I am trying to keep my cellphone number after closing the account and when I reverse the payment they threaten to cancell my phone number that is now on a prepaid number.. I have paid this account in full during my contract period and how can I stop the payments they ******* takes from my bank account. There was *****elent activities in the branch in Kempton Park, Glen Marais, where I went to close my account. How can Telkom just go ahead doing what they are doing and ignore my request to close and cancell my account. I have paid the full contract period.