game unistalled itself mid que????????? ( RED Respond pls)

so i was in champ select the game was loading in and it froze in loading screen, it was stuck at 20 % so i alt f4 nothing happen then i said okay ill reset pc and then come back little to find i start league and the game had to reinstall 5000mbs of data so it basically had to reinstall now i lost that ranked match it was not my fault and now i have a leaver buster again not my fault id like to get info from a riot employee as to why this happen why the hell would your game just uninstall its self?