Improper charge

I requested a contract cancellation and change to prepaid. I sent an e-mail and faxed a cancellation form on 5 January 2016 to their cancellation department after the inept agent advised that I must sent the form myself. On 5 February after still hearing nothing I went to the same outlet (again standing in a queue for half an hour) and found out nothing has been done. I logged a case number with another much more capable agent, and after several frustrating follow up calls I was notified approximately two weeks later about the cancellation. I ported the number to another network. This morning I received a bank notification of a debit order of R 895 was debited to my account (The 2 year contract period ended 10 January 2016). My monthly subscription cost was R 279. I was not aware that I owed any amount, but certainly not R 895. I called customer support and despite my disappointment in Telkom the agent was very helpful. She logged Case number: ***2. Although she said the case will be attended to within 72 hours, my experience with Telkom has proved that things never go so smooth, so I am looking to your to also attend to the query, before the matter escalates