Harsh 5 game 20 minute LeaverBuster

So as of August, I have been playing League of Legends with a more "slow processioning" Laptop which still allows me to play the game, just not at a 100% satisfaction. At times my FPS will drop below 10 making the game "lag" and the current Wi-Fi that I'm using isn't very helpful when that time comes, which understanding that my laptop isn't at its best to preform these measurements, I don't feel like I should be punished for something out of my control, regardless of it being one non-ranked game. My game crashed during the Champion load in, and I had to re-open my Client and re-log in, to re-connect into the game. I was only AFK for 6 minutes and played at a positive kill/death ratio. I felt that my 6 minute absence wasn't the cause of our defeat, but since I can't defend myself against being reported, I obtained a 5 game 20 minute LeaverBuster from my team members, because they reported me for being AFK when it wasn't my fault that I was absent from that game. I'm not saying that it's okay to be AFK, nor am I saying that It's okay to leave a game prematurely. I'm only lashing out because I felt that my punishment was to harsh when I had no control over the situation, I did come back into the game and continue to play until we surrendered, and even though I was sportsmanlike during my return I was still harshly punished. I don't blame my team members for reporting me, I only feel that this punishment is unfair and unreasonably displeasing to me.

Thank you.