Contract not cancelled resulting in additional billing

I called Vodacom a couple of times in the last 3 months to have my data contract cancelled. The contract should have been cancelled in July but the administrator apparently did not cancel the contract and I found this out when I got my statement I saw that the policy was not cancelled.

I have since logged a service request with ref: *** but I have not received feedback. I am not liable to pay the August amount as it is not my fault that the person did not do their job. I want this reversed from my August statement. And I would like someone to contact me. Poor customer service