If it's extra-curricular (by which I'm thinking that means *at the school,* or *school-affiliated,*, like drama or sports or clubs that meet after school hours, how would that not be "a school activity?" Most extra-curriculars take place after school hours, don't they? Unless you're talking about church-affiliated Boy Scouts or something, I don't understand how anything that is related to stuff the school offers would not be a school activity.
And obviously I think you should keep bugging the relevant authorities until they come through with whatever it is your son needs.
