I JUST LOST LP FOR A WIN

I'm soo frustrated at the moment I recently played a ranked game (I played Renekton) where everything was going great everyone was winning their lanes and the jungler was amazing. I unfortunately disconnected twice during the game due to connection issues and restarted my modem in an attempt to solve the issue. I return into the game 3-5 minutes later and help my team win the final teamfight and win the game. In the end game lobby I was marked as leaver and -19lp, but in my match history I simply obtained a victory. Like I get it I disconnected and almost ruined the game and need to upgrade my internet connection but man I got punished for coming back into the game and helping my team win. I'm not crying for the lp for the win but at least return my lp before that 'leaver' win its getting hard to climb in end of season enough already these step backs hurt