How would you deal with this?

[Mailfuckoff]

Ds (9, but young in himself) had a bad morning

1. He wouldn't feed the cats (his chore) so someone else had too as cats were hungry
2. I heard him swear which is an automatic ban of computer games for today
3. Because of this he ripped up the birthday card I gave him (his loss really)
4. Because his brother is taller then him so doesn't need a car seat anymore he went into his brothers room and smashed up his lego

He's now at school. Punishment wise he has lost computer games for the swearing and taken toys out if his room to earn back for the smashing of lego. We will have words tonight about cause and effect and other people. On Thursday normally he has tea with his grandparents as a treat. Should I still let this go ahead as his behaviour this morning was not acceptable. He sees his grandparents every Thurs and Sat so missing one evening isn't going to ruin their relationship. What else if anything should I do?

Update: dh decided he shouldn't got to grandparents and is picking him up from school. Need to do something productive with him but when he's in a destructive mood it's difficult

Any idea's?