I have been banned from League of Legends for something I didn't do

I got an email from riot yesterday telling me that I was banned. I honestly thought it was a joke, but today I wrote an email back because I was still worried. Turns out it wasn't a joke. I am banned forever due hacking, scripting or using a third party software, something that I didn't do. I have been playing this game for over year and I have over 700 hours and 300 dollars spent on the game. Why in the hell would I cheat. If you look at my op.gg, I'm a silver 5 player with a 50% win rate. My summoner name is Nextazo. My last game was a 8/9 Kass game, which I did the worst on the team. I am not a criminal nor have I disrespected the community by making the game unfair for others, though sometimes salty, I am someone who enjoys making the game fun for others. I have never ran down mid when I lose my lane, I have never feeded when upset with team mates, and I have never cheated to make myself look better at the game. If you are reading this, as a follow player I ask for your help. This is unjust and unfair. I haven't even got a specfic reason, just " you have broke terms and conditions" and they won't share the reason why. I am not a criminal, just another 17 year old trying to play his favorite game. I don't want this mistake on riots part to ruin the game for me. I don't want 700 hours of my life gone due to this along with 300 of my own dollars.