Losing LP after winning a game that got crashed

So i just played a game of vayne. at level 5 my league suddenly froze, also my computer. so i restarted my computer. I got back in like 5 minutes after and started to get back into the game. We won and i lost 17 LP. now im super tilted and not in the mood to play atm. Riot please review that game, cause thats bs.