Got a 14 day ban with no prior warning or chat restriction ever for the first time in over 5 years?

So I got banned for the first time since I made my account in season 2. I've never been chat restricted, and i've never been warned before in the entire time I've played League.

The game I was banned for, this guy was flaming me and decided to int because our bot lane wasn't doing so hot. I got tired of him flaming and running it down and this was my chat log.

Game 1 Aezis: yep Aezis: imma auto him a lot Aezis: this xin Aezis: xin is camping us so we have to just sit under tower Aezis: tru Aezis: jax Aezis: dont bait us Aezis: like that Aezis: didnt u get solo killed like 5 times talon? Aezis: when we got camped Aezis: do you know english? Aezis: learn english buddy Aezis: %%%%%%%%%%% bing bong? Aezis: talon u china Aezis: like china town? Aezis: %%%%%%%%%%% bing bong? Aezis: bing rong ring dong? Aezis: i know chinese too buddy Aezis: ggwp

Was this inappropriate on my end? Yes. But is this really subject to a 14 day ban with no prior punishment since my account creation in season 2? I wouldn't think so. How is this guy allowed to flame and int with no punishment, yet I get a 14 day ban for messing around with him? I didn't call him names, or anything of that nature. I was frustrated at this guy for running it down, and this was my way of venting it. Had I got a chat restriction instead, I would've known better in the future and I wouldn't say anything that's unhelpful or offensive in the slightest.

What I said was wrong, but this punishment is way over the top.