I have not owned my Trailblazer very long, but I have noticed on every Trailblazer I have seen there is a problem with the front bumper. It is warped and wavy. It looks like it is a problem with all of them, and the dealership said they have never heard anything about it. Hard to believe since I counted 15 Trailblazers with the same problem, just on the way to the mall. My truck is white so it shows really bad. I am taking it to the dealership this week.
Trade it in for a Pontiac.
A good dealership will find the service bulletin and glue it back down according to the factory instructions.
I have read about this in a few message boards. Mine is wavy too, but I didn't notice it until I read about it and looked. I haven't bothered getting it fixed. Maybe it is more noticeable in white and some other colors (mine is silver).