Refund outstanding for nearly two months

I cancelled my internet service with Amobia, gave a month's notice as required. They took 20 days to read my email requesting the cancellation, and then took another month's money from our account (About R800). I have called and was told that money will be returned to me. I called at least twice a week now for the past month and a half. Every time I am promised that the refund will be processed and up to this date it has not been returned. I DEMAND immediate return of MY money.