Unhelpful and plain rude

I phoned in to place a order to get a landline. I first requested the pricing and then I specifically asked about the installation costs. The lady told me if I am a new customer, the installation is free. I then said okay cool put my order through. It took her around half an hour to place my order. At the end she tells me the system says you have to pay a installation fees of R620. I then said to her I specifically asked about the installation costs. She says yes the system is giving that cost. I asked to speak to her supervisor and she says he is not in the office. I spent more then half an hour on the phone. I also didn't get to confirm my order cos she put me on hold and never came back on the phone.