Gents, it's too late, I'm already in head office...
Now having said that, I have been on the wrong end of fatigue myself on numerous occasions, but please don't play the fatigue or safety card too often. When it's warranted, then shout it from the roof tops, but I've seen too many people try to stop any changes or even discussions about change on the basis of what is often a very tenuous association with safety or fatigue issues.
Senior management often roll their eyes at the mention of it and the battle is sometimes already lost. In this case, I'd call wolf on this being a fatigue issue.
This is just a whinge about rostering. If it was scheduled within the approved FTL scheme and there was an FRMS in place to monitor fatigue levels, then I wouldn't be too quick to dismiss the fact that someone is just having a moan without a lot of ground. One thing I know is that our lawyers have naff all say on what gets put in our FTL scheme!
If you are fatigued, then you know what to do. Call crewing and get someone else to fly in your place. If that is an issue in your organisation, then find somewhere else to work that isn't so awful.