Sounds like your customer has the system set up to immediately put the agent ready at the end of the call. My experience is that small call centers often are trying to get calls to agents as fast as they can, and end up setting up things like this. Ultimately, they find (as you're seeing) that these approaches usually aren't a good idea.
Your first to do would be to probably reset this so that the agent is not ready at the end of a call.
You can also set the agent for automatic work to give them wrap up time at the end of a call before becoming automatically available again. The agent can go ready faster, but the system won't automatically put them available before that period expires.
