Game Freezing in ranked!

I quit the game a few months back and forgot why but apparently i was fed up with every few games my screen freezing in the game and i couldn't even tab out to force the program closed to try to restart it. Instead i would have to resort to hard booting my entire system... this left me and more so my team mates frustrated because this would take about 5 minutes to do and a lot can happen in that time. It would be great to get a resolution to this game problem or get a refund in the money i invested in it as i cant even enjoy the fruits of my labor. This is the second time this has happened and resulted in a leaver buster low priority queue.