Drop phone call when you say you are not interested

How does MTN employ people who is so rude, the lady phoning all happy and insisted me on taking a "special deal on a Samsung, as soon as i told her i an not interested at this stage she kept quite and after is said hello again to hear is she is still on the other end she just kept quite (with other people in the back round) and she just dropped the call.

The way she handled herself was disgusting and gives MTN a very bad reputation!!