Cell phone contract terminated however I am still being billed

My cell phone contract termination notice for both cell phones ********** was submitted to Luyanda Tsoanyana on the 20th July 2017 which was suppose to terminated on the 30th of August, however due to the incompetence of the these individuals my account is till being debited even after I reversed the money last month from my account and no communication has been given in terms of the way forward. My account was also debited on the 02 November 2017, with the amount that I reversed last month and the current month. I am currently unemployed and this is creating an inconvenience to me because the bank is charging me extra for insufficient funds.