Vodacom not refunding me

My Smart S contract ended in January 2016.<br> I was notified in February that I still had an outstanding amount of R618.47 which I paid at the Vodacom store in Cresta on the 27th of that same month. A few days later Vodacom debits my bank account for the same amount. On the 10th of March I logged a refund request and provided the requested documents. The agent told me it will take 7 to 14 working days to process. Its almost a month later an I havent received my money or even a sms from Vodacom. This is the reason why I cancelled my contract. I demand immediate action!!!