Very unhappy pensioner

I would like to start by saying that I am posting this review on behalf of my grandmother. She moved last year and moved her Telkom lines and after being at her new home with a new line and internet she received a message to say that she was out of bundle (after 4 days a 73 year old lady used a 100GB) this is impossible. Needless to say after contacting the call center nothing happened and she still did not have internet.....this left us no choice but to cancel her contract with Telkom. I have all the correspondence dates and times, messages received, emails sent and replies from Telkom acknowledging that the contract was cancelled, but still the account keeps on accumulating. Now she has been handed over for debt collecting for an account that should not even be there. We are absolutely fed up with this situation and really do not know what possible steps to take to get this matter resolved. I would not recommend Telkom to anyone as they are absolutely useless with their accounting system, there is no communication and not to mention their non existing client services. They simply just do not get back to you or follow up on queries.