14 day ban after 9 years of solid service??

So, I have been playing this game since, i don't know, almost the beginning? I remember when this thing was still being compared to the original DOTA map. No, not DOTA 2, I mean the MAP, from WARCRAFT 3. I have been playing since near WARCRAFT 3.

I was having a heck of a weekend - vagrants soliciting me for money, tweakers getting work in my company over me, family acting strange - I just wanted to play some normals. Just for that League experience. No ranked, just gameplay.

I get into a match on a late Thursday evening, and within five minutes the ADC is saying in all chat that I am bad. I am not sure five minutes is enough time to evaluate skill.

Well, I will shoot straight; I was mean. I was excessively mean. I spent the entire forty minute match asking this person where their trash talk had gone. Besides a couple times where they had the time to reassert, of course, that they felt I was bad, they didn't reply. But I was mad, and I allowed myself to continuously ask, to the point of being obnoxious, where their trash talk had disappeared to. After all, even if we are winning, shouldn't you stick to your guns and insist someone is bad regardless of how the match turns out? That is what I was expecting.

What I got, however, was a FOURTEEN DAY BAN several minutes after the match ended. I didn't report the guy - obviously he was intent on being a jerk without even experiencing my gameplay - but myself? I may have said some things I wouldn't really mean to a fellow player, but is my first and only offense really deserving of a FOURTEEN day ban? That, to me, is extreme. I am all for punishing unsportsmanlike behavior, but does every first time offender deserve that kind of ban?

I have been playing League of Legends faithfully for nearly 9 years. I have invested much time, MUCH money, and much dedication into making this my hobby. Is it really fair to impose the penultimate penalty at first offense by a dedicated player?