Debit order going off months after cancellation

We have two cellphone contracts that we cancelled to be carried on, on pre paid / pay as you go. Cancellation form was sent through the first time on 11/8/2015. Then we were given a different email address to send it to the beginning of September. After numerous emails to and from Bianca Delo we just keep getting the same response of \Kindly take note that i am attending to your Telkom contract cancellation request"and the contact no she has on her email 081180 was called"