banned for inapropriate behaviour

Look, I don't know what kind of relationship exactly you 4 have with each other, and I'm sorry if someone's being excluded from a group, but drama between a group of people is generally not staff's problem to deal with. If guys for whatever reason can't get along, then you probably shouldn't play with each other. If it doesn't break the server rules and no one is being outright disrespectful or doing something that is clearly not okay, we can't really do anything. Such stuff is up to both parties to either resolve or deal with one way or another. Players have access to the /ignore command for a reason.

As revenge for something that is not a problem staff can do anything about, you decided to break the rules and create issues that staff have to deal with. Namely claim griefing, building something inappropriate, and killing a player with lava. That's not okay dude. Not only are you breaking the server rules, you're adding fuel to the fire here. Two wrongs don't make a right.

Your temporary ban (which is actually for 3 days, not 2) will remain.

Breaking the rules is not the solution here. Not for you, and not for anyone else. It's up to you guys to either resolve your personal issues with each other, or go your own ways.