First let's get these out of the way.
- It's possible you don't remember getting a 25-game chat restriction if you've gone a long time without playing. The thing is the only way to improve your account standing is to actually play games and show improved behavior in them. Simply going inactive for a long time doesn't work to improve it.
- Your overall attitude here is not helping your case. By picking fights with people who disagree with you and accusing them of being "part of the group that's the problem" you're only giving people the impression that your ban was actually deserved. This is something allot of punished players tend to do (turn hostile in the face of opposition) and it just ends up biting them in the butt.
- "They started it/were worse" doesn't work here. Everyone is responsible for their behavior and is judged based on their own behavioral history. This means that something that got A a 14-day ban might only get B a 10-game chat restriction if B has a less consistent history of poor behavior.
- It only takes 1 report to flag a game for review, which is then thrown out if nothing of guilt is found. Multiple reports don't change this.
Now onto your case:
Early on it's easy to see that Malphite is causing trouble for everyone in the game, and to your credit you do try decently well to get everyone to focus on the game game and not the blame game, though your approach could've been a bit better, such as not being so eager to give up early on. Where it starts to go downhill is here:
PamP00vey : LMFAO
PamP00vey : Okay
PamP00vey : False reporting is also reportable
PamP00vey : Go ahead
PamP00vey : I'll do the same
PamP00vey : Okay, boomer.
PamP00vey : I didn't int, no one followed up.
PamP00vey : But thanks for the abusive chat report.
PamP00vey : That will go nicely for you.
PamP00vey : Okay. ^^
PamP00vey : Get reported as well.
PamP00vey : 1-6
PamP00vey : Awh.
PamP00vey : false reports reportable
PamP00vey : go ahead
PamP00vey : I'll do the same
PamP00vey : Enjoy the abusive chat ban tho
PamP00vey : Imagine being a jerk in a video game
PamP00vey : Awh.
PamP00vey : Ego so fragie
PamP00vey : I'm not toxic.
PamP00vey : I haven't said a word that's toxic.
PamP00vey : what did I say that was toxic, Nunu?
PamP00vey : Name it.
PamP00vey : Awh.
PamP00vey : I really don't care, you'll get chat banned.
PamP00vey : Okay. ^^
PamP00vey : Enjoy
PamP00vey : It isn't a threat. It's happening. Go off.
Pretty much all of this is pointless arguing, provocation and taunting, not to mention calling for reports coupled with some insults here and there. Everyone already has to deal with the Malphite, and all this accomplished is turning you into another problem player your team has to deal with. Sure the Malphite was being toxic, but can you honestly really say that this behavior of yours makes you any better than he was? Sure you weren't slinging curses or slurs but you were still going out of your way to provoke him and basically contribute to the negative atmosphere of the game, something which Nunu clearly noticed and called you out on. In that aspect Malphite won by dragging you down with him.
Also, I find it interesting and somewhat ironic how the very first line you spoke was this:
PamP00vey : don't be negative
Yet you spiraled down into negativity the further the game went on.
Advice:
Mute the problem players instead of arguing with them. Most people who act up in chat are looking for a negative reaction from others. If you don't give them it then chances are they'll shape up and focus their efforts on the game. This doesn't always work but it's better than the alternative, and at the very least you don't run the risk of being dragged down with them.
Don't intentionally try to provoke people into being (more) toxic. If they're intentionally acting up then you're just one more toxic person to deal with, and if they're not then you're only contributing to their frustration. Either way you're just being a bully that's sealing their own fate.
Know when to stop. I get that this can be hard to do especially in the heat of the moment, but sometimes it can be worth taking a step back and thinking if it's really worth it to continue trying to converse with someone who's not being receptive. Refocusing your efforts on the game is more important and better in the long run than arguing with someone for the majority of the game is.
What you do with this analysis and advice is up to you, but just keep in mind that your account is on thin ice now. Any further problematic behavior will result in a permaban. You've been warned.
My Verdict: Punish.