Remaining calm is the first step when handling an angry or difficult customer. Listen to the customer. When people are angry, they often just want someone to listen to their complaint. Try not to interrupt the customer. Apologize to the customer sincerely. Whether or not you find the customer's complaint valid, you must politely and sincerely apologize for the trouble she experienced. Take responsibility for what went wrong and assure the customer that you will work to find a resolution that will satisfy her.