Worst service!!

Can someone please explain to me how it is possible to be debited for a contract that has been cancelled for 4 months. My contract had been cancelled last year. The first month after cancellation my account was debited but then ratified by Telkom without me having to let them know. Which was great but now every month since my account is debited for a contract that I don't have plus I don't even receive the benefits as if the contract was still active. This month my account was debited almost 2 times the actual amount of what the contract was for. I have lodged numerous queries about this and keep on receiving emails stating case closed without as must as a phone call or email about my issue. I have now blocked Telkom from debiting me. They can sell you a contract within 5 minutes on a phone call but it takes them 4 months to cancel a contract and stop debit orders. Worst after sales I have ever experienced in my life.