Game crashes Mid Game

I can't play league no more cause my game will crash when i load into the game or during the game my screen would go black and i would have to hard reset my PC and i know my PC is not the problem its the game cause sometimes when im lucky the bug splat will pop up and i would relaunch the game and when i load in... My screen will go black again and i would have to hard reset my PC and im tired of this shit.... I sent so many support tickets and they are just saying to install the repair tool thinking i haven't done that yet.... These riot workers need to get off their ass and start working on the bugs/problems this game has. its fucking pathetic