The promotion structure is based on time, not ability, meaning many of the people in charge are absolutely terrible managers, but since they've been there a while they end up in positions of power. Equally bad is the inability of entry-level employees to move up in duties and responsibilities. After three years you should expect to be doing exactly the same things you were doing on day one, no matter how much you prove yourself or how invaluable you become to your team. Then either accept it or quit - like most people do when they realize they're not going anywhere. Every other week they announce a new departure, but no one in HR seems to care about what's causing that - people are disposable.
