Rebellion for being Punished

Question:

I am having problems with my 2nd grade son. Recently, he was suspended from riding the bus after hitting another child back after this kid hit him. My son was suspended for 7 days, while the other child received no discipline at all.
For the last week of my son’s suspension from the bus, he’s been a pain in the tush! He came home Tuesday of this week and in school he was bored and cut his sweater sleeve! Yesterday he came home with purple marker all over his palms. He says he was bored [again].
Today I received an email from his teacher that she wasn’t clear about my signature on a time out notice he received yesterday in class for not paying attention, and I never even saw the notice…I think my son signed my name to it.
He doesn’t act like this regularly, only the past week that he has not been able to ride the bus… HELP…please I have no idea where to go from here. I want to yell & scream at him and then I want to hug him and cry… I don’t what to do. Sheila