False debit order

My grand mother has been trying to cancel a debit order with Vodacom for 5 months now. This debit order is being charged for a phone she did not end up purchasing. In store staff cant help her and the finance department promise to cancel it and never do! She calls them using her own airtime to be passed on to the next consultant and gets told it will be canceled and yet another debit order every month! They are *****ing a pensioners money as far as I'm concerned, disgusted!