Debit Order on Cancelled Contract

I requested a premature cancellation (September - December 2017) on my Vodacom contract and received an invoice mid August which I paid in full in August. I was asked to email my documents and payment to ********** and in turn I would receive a reference number.

I did not receive a reference number and called Vodacom multiple times to request the status of my cancellation - the accounts department verified that they received my payment as it reflects on the system but still no cancellation.

I had multiple consultants tell me the cancellation takes a few hours, 24 hours, 3 days, 30 days - not one consultant could give me an accurate answer.

I was eventually told my contract will cancel the end of October and I will not be charged because my account was paid up to December 2017 - yet I received a debit order on the 1st of October? My contract was eventually only cancelled and converted to prepaid on the 5th of October.

A month later, I am no longer a Vodacom subscriber yet my debit order went off again on the 1st of November. So how is it possible that I paid my contract up in full AND I am still being debited on a monthly basis for something that has been paid for already?!