Don't treat your staff like you currently do. You haven't a clue how to motivate people, or make them feel valued.
Have some respect for your "associates" by clearly informing your team leaders what the contract states about holiday policy, and actually implement a clear system of holiday request. Also, value the work of agents, they without any question have the hardest job of all.
Effective and continuously training, mitigating doubts and questions during the phone call during and after training period.
Be more understanding .
Make sure staff are looked after.
Reward work and quality people, don't hesitate to dismiss the bad apples
Offer a better training programme
Use trainers who aren’t arrogant and full of attitude.
Follow what Richard Branson says, look after your staff, profits will follow.
I think they have a review and try to accommodate as best they can depending on the circumstances