Most modern anger is derived from helplessness. I don't get angry when I spill my coffee or someone cuts me off on my commute, but I recently discovered that I've been overcharged for my cell phone plan for the last 18 months and it made me seethe, mostly because I know that it's going to take a half dozen phone calls over at least as many hours to come to any real resolution, and that millions of people are likely in the same predicament.
Writing all that down made me more, not less, angry.
Anger is only a problem when it shortcircuits logic and reason and makes you behave irrationally and in ways you later regret. But used effectively, it can give you the energy you need to get through all 18 of those really frustrating phone calls before you give up.
It happened to me, I called and talked for an hour and managed to get my money back. I finally got the person on the other side of the phone to agree to “discuss with my superior” after asking them to describe what the word theft means and explain me that adding a service without my request and charging me for a year did not fit in the description.
Then one day later I requested to move my phone number to a different company.
Then they called me back telling me they could permanently lower my bills, and made me even more angry :)
I’m still happy I never paid them another cent, but in the back of my mind I know the company I moved on is doing more or less the same tricks.
An exercise (whether writing or verbal) that helps me redirect or alleviate some of the anger is to simply ask "How do I imagine that person might be feeling?"
The trick is, when I'm feeling angry, I don't often want to answer. But when I do, it can help me realize that the current situation may also be hurting or frustrating the people who had been the targets of my anger, and then maybe we can work together to get rid of the problem. This seems to help me when calling customer service, because now I'm not fighting against them but fighting alongside of them.
Writing all that down made me more, not less, angry.