I've dealt with many difficult clients in the last 12 years, and I find what works best is just putting myself in their position, having an understanding of why they're frustrated, being compassionate, but also controlling the conversation, redirecting it so that you can be productive and actually make headway for them. If it becomes too heated or things just are not resolving over the phone, you can also just say, hey, I'm going to get off the phone here so that I can either confer with my attorney or do a little bit of research, find out how I can help you, but I will be calling you just as soon as I can. And then when you say that you're going to do that, you actually do it. You look into whatever their issue is and call back with an answer. Usually if you both have a little bit of time to breathe and think about it, it resolves itself. So just dealing with things tactfully.