Networking at moments of truth

Have you experienced a bad attitude when you ask for some information? The past week one of our candidates left visibly upset after having interaction at one of our service points. We couldn't help him at that moment, and the next day I have to take care about the situation. The conflict management is one tough but excellent opportunity to do Networking:

First: Get all the evidence and information about the client you are about to contact. The most information on when he arrived, from where, by which mean he attended our service point, what information he was seeking, everything that can help to give your potential customer information.

Second: You have to plan a strategy, if the information is about your products, maybe you have just to translate the message to be appealing to the candidate and then explain him the information.

Third: Do the contact, by phone or asking for a personal meeting. I wouldn't recommend to send an email, because your customer is angry and now it's your opportunity to repair the damage. Maybe ask him for a 15 minutes call so he can explain his doubts.

Fourth: Before you ask him about why it made him upset, tell him that you noticed there where some aspects of the information given that kept without an answer, and that the call is to explain a little bit more the information.

Our candidate wasn't that much upset, and he showed a little surprised and thankful for the follow up. He told me that there were some questions that haven't been answered and gave me some recommendations on how to train people to avoid this type of incidents on the future.

And you, have you had some of this moments of truth solved in a different way?