We've been here! And after two years of asking the school to please please please do something, we finally pulled him out (last week!)
DS can be very disruptive and distracting, especially if in a class he's not interested in (e.g. it's stuff he knew a year ago). He is not a people-pleaser in the sense that he won't just "buckle down and do his work" because the teacher asks, but he is more than happy to do something goofy to make the other kids laugh or pay attention to him.
While this sort of behavior was mildly tolerated in his 1st grade class, it got worse and less tolerated in 2nd grade. It resulted in being sent to the office more and more frequently, which had no effect on his behavior, and didn't help him feel good about himself or school.
In my experience, the best way "to get through to him" is through logic and knowledge and allowing DS to try to make the right decisions himself. Telling him to do something generally doesn't work; giving him information so he can make the decision to do something is usually more successful.
I'm not sure what you can do to get the school to do its job. I can understand why your son doesn't want to do the more challenging work packet (we tried the same thing with DS, with almost no success.) Ultimately, after many meetings with his teacher and principal, we decided that school was actually doing more harm than good.
This is probably not an answer you're hoping to hear. I'll be watching this thread for insight myself!
