Contract still not cancelled after numerous calls!!!

Good day. My husband has cancelled our contract on 14 March 2018. We were told it would take 30 business days. Once the period was over we still got billed and the debit order has once again now been deducted today. Even though Telkom confirmed the contract has been cancelled plus debit order has been cancelled when he spoke to them on Monday 30 April. How is it possible that we are still paying??? This is blatant *****ing. Contract name Gerhard Barnard. Really hope somebody can help because the call centre has been useless.