If I were you, I'll go.
Firstly, it saves the trouble of parents explaining something that
you've done.
Secondly, you can learn something with guidance, which is free
somemore.
Thirdly, you can gather with your friends to talkcock sing song,
which is much better than playing rpg and surfing porn.
BUT, if you really don't want to go, just call your parents to call
the school, if the teacher threaten you to cough out the
money.
Anyway, it's up to you to learn something new or just at home
playing rpg.