Riot takes trolling very seriously and you can get banned for trolling
http://boards.na.leagueoflegends.com/en/c/player-behavior-moderation/1cvmXAWA-permanently-banned-never-said-a-word-no-email
A WOOKIEECOOKIE smite on a person who thought that because they didn't chat they wouldn't get banned.
Your current case wasn't found by our PB detection systems but it was hand reviewed by someone in Player Support. The account was locked because the degree of your behavior and the frequency it was occurring was creating a terrible experience for other players. Because these bans are 100% reviewed manually, a reform card is not sent. You're free to contact Player Support for more details.
In your case, you are correct when you said you didn't chat, but your in game behavior was often much worse then a few toxic words. This wasn't behavior in one or two games, but a traceable pattern that goes back a few months. Intentionally feeding, blowing summoner spells at random times, buying multiple boots, multiple tears, teleporting into base and running back and forth and of course, the non-stop pinging that you would do to your team mates. In fact, when you get really upset it looks like you just decide to ping all the time stopping only for the forced cooldown period and then starting back up again. Even when asked to stop you continue to do it for no real tactical reason. Perhaps to force an early surrender so you can get to the next game since you know that pings are not currently mutable?
Regardless that behavior isn't acceptable and intentionally trolling games and ruining them for others can and will result in your account being locked.