Annoyed

I used to have 2 Contracts with Vodacom, early 2016 Vodacom was requested to update / change my banking details for my debit order to run. 1 was changed but not the other. In September I cancelled the one contract, and had the last debit order run for the account that was never updated, and without my knowledge (as I dont actively use the account anymore) the debit order bounced. Vodacom never made contact with me in this regard. Upon a query on my still existing account, they advised me that my account was in arrears, and when I questioned this, it was brought to my attention regarding the bounced the debit order. I was advised that I needed to either do a transfer or go into a store to make the payment. They charged me a fee of R100 for the bounced debit order. I went into the store to do the payment, and a week later they proceeded to do a further debit order for the "unpaid" amount. I logged a ticket with the call centre, and was advised he could see the double payment, and they would refund me the one payment. 7 days later I called to follow up on the payment, and was advised they needed me to fax through the proof of payment - which to me makes no sense as they acknowledged the double payment. A further 7 days went by, and I followed up again.... and I am still waiting for my refund. Shocking that they are so quick to charge for a bounced debit order (after they were instructed to change / update banking details) but cannot refund you, what is rightfully yours, and an error on their part.