The way to promote quality customer service is through incentives and fast food restaurants with typically high turnover are not going to provide this. Their minimum wage, mainly high school employees are notoriously unreliable.

The only way to fight poor service is to stop patronizing the restaurant. There is a Burger King nearly across the street from our offices that has had horrific service forever. Recently they hired a new manager and it appears service has improved. She even reached out to local companies so the store knew there were issues.