When dealing with difficult clients, the best thing to do is try and be very understanding of what their needs are and what their issues are with regard to their problem. Really understanding and listening is the most important thing. Just trying to stay calm and reiterate to them that you're going to get them the answers they need, and if in fact you have an issue or have difficulties with solving that problem, make sure they're told that they will definitely hear back from you if in fact you need to get back to them. I always believe that it's best to stick with the one person that they voiced not to switch them off to other people in the company, and to be switched around a lot only makes their issues a little bit more difficult.