2-week ban justified for reasons other than what the ban was for

So recently I was instantly given a 2 week ban right after getting out of a game with a guy that decided he had enough and was as he said "afk'king %%%gots." I made the mistake of quoting this in all chat and asking for a report. This triggered the system and me being fresh off a 25 game chat restriction was slapped with this. To explain why I quoted it in all chat: DC's happen. But this one was obviously spiteful and he used a homophobic slur. I was letting the enemy know that hey he isn't just having internet issues he's actually upset and purposely left. I was recently coming off a 25 game chat restriction (deserved). I was watching what I was saying to people and making sure I didn't cross the line so this insta 2 week ban seemed like a mistake. I opened a ticket, explained all this and the ban was upheld for other toxicity i displayed as Borrower states. I can understand their side. I wasn't being the perfect summoner and need to learn to just not type back to people. But, I don't think anything else I said was deserving of a 2 week ban. I should've worded why I wasn't going to step foot in a fed draven's lane better but I was frustrated with how the game was going and why the only lane arguing and being toxic felt they should request the jungle camp there lane. I'm also fairly certain the afk'ing player and there duo reported me because they were both coming at me pretty hard in game chat while I kept my cool and tried to tell her her reasons for saying what she said are wrong. Am I wrong in thinking this is unjust? If someone else from the support team could give me some insight on how these things work and how to avoid this in the future that'd be awesome. Thanks.