League of legends entire patches gets deleted on force closing the client.

I was playing a game and sudennly the power went off... after about 5m it came back so i launched the client and this message poped out "We have restored this installation to an older version of League of Legends. Now we'll try to patch it up to the latest version." I went to the league file and i found that the size of it were actually reduced and the latest patch i installed were completly removed. It happened to me another time whene i closed league from the task manager it was one processus that was still running even tho i closed the client normaly and because i force ended that process it deleted the latest patch. I don't know if this intentional by riot like an anti-cheat mechanique or something but this is happening to people in ranked games, and not every one have a good internet connection to fix that fast enough, like my self i only have 1mbs network, i know people are having a probleme patching their clients after this happen but i never had that probleme and as i saw someone found the solution of set the date and houre to a prior one of yesterday with 1 hour earlier. I want to find a solution for it not to happen in the first place.