Debit order cancellation

I have been to the Telkom branch in Cresta to cancel a debit order going off my bank account as i do not have a contract with Telkom. I took my bank statement with to prove this. The lady who assisted me logged a query with Telkom Mobile to call me in 5 minutes. They didnt and after 15 minutes she called them directly to which i waited another 15 minutes and no reply. So i said i will call them today. I called at 08:00am and spoke to Brendan Joauwana and advised that i want to cancel a debit order and have the contract holders info. He sent me a form to cancel a contract. I mailed him back to advise that it is the incorrect form. and still have not received feedback. The contract is in my ex husband of 7 years name. Why cant my bank details be removed from his contract and you contact him for his bank details as this is in fact *****. Telkom is committing ***** by debiting my Bank account and i do not have a contract with them. PLEASE can someone competent assist me to take MY Bank details off of someone else's contract.