Intentionally feeding ban

I have banned for 14 days on league of legends and was banned for Intentionally feeding , I was trying to fight a nasus that I could not fight and I kept fighting it when low and I kept dying over and over and they said I was feeding which I was sorta I was trying to play the game by killing the other opponent and I could not so I roamed to get kills and I got some so I thought I could just farm their lane, but instead I fed their lane twice then went back to top and died once more , so what they thought when feeding I went into the enemy base because I thought I could kill the trydemere, and after I died I switched to ap because someone in the game before that siad to a riven top while I was jg that ap riven was broken so I had to try it. and after that game I played riven, I started of ad got 1 kill switched to ap got a kill that was alot easier, and I kept surrendering because I knew we had lost because nasus is very op late game and they said no and I couldnt afk because that would get me banned too so I kept trying to stay behind, but I kept dying and they reported me. I do think that I should get a 7 day ban because of how bad I played but I do not think I should get banned for 14 days.

 Thanks for listening-HappyKermit