Anyone who has operated a dining establishment for any length of time is well acquainted with customer complaints. While contentious customers are certainly not the norm, they are something that has to be addressed.

Whether it is a complaint about service, quality, or cleanliness, it is important that you, your management and all staff members knows how to diffuse a potentially volatile situation and turn it into a positive dining experience that will have the customer coming back again.
Courteous Attentiveness
When a customer has a problem, your employees on the floor are your first line of defense (and often bear the brunt of the customer's displeasure). It is crucial that all serving staff is trained to listen and be courteously responsive to the customers concerns. The employee should be able to repeat the customer's complaint in a way that shows that he/she understands the problem and desires to rectify the situation. A prompt apology can help defuse a situation before it gets unnecessarily negative. On the other hand, a reactionary and temperamental employee can easily escalate a negative situation into a catastrophic one.
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Dealing With an Upset Customer