4 answers
Some agents are not doing their jobs properly but it is overlooked when they get good surveys but when you look into their work, they have no passion for it. They are only working for compensation. Some faults are by the clients but they do not want to tell the clients as they don't want to lose them but hiding those faults made customers angry with the customer support agents and with the client's company and products.
Pay your agents more and you will see better results.
If you want to lower the incredibly high turnover - increase your incredibly low wages.
Our CEO is intelligent enough but one thing I want to suggest, it is the promotion process. It takes too long based on what I observed, that's why others can't wait that long (6 years onwards) though there are capable for this.