There are 3 things which I believe can help agents keep their job:
An outgoing and friendly personality.
This is hard to show because the clients are being serviced over the phone. the voice, the choice of terminology and the manner of saying the words play an important role here.
This makes everything possible for the agent to deal with customers making them feel as the most important people in their existence
Learn to listen carefully and never butt in while customers are talking. whatever they are saying, let them finish first. always acknowledge and let them feel you are more than willing to assist and help them the best possible way you can.