Black screen had to uninstall

Got a black screen everytime I logged into the game for some random reason, had some issues with my graphics card and did some fine tuning. Now I had to uninstall LOL and get it going, and now RIOT is giving me afk bans... Really?! YOUR BANNING ME BECAUSE of TECH DIFFICULTIES?! I pay you 100s of dollars a year in this game, and this is the thanks I get?! I can't wait till somebody out there gets smart and builds a game that out ranks yours 10-1... till then I have to admit, LOL has the best PVP out there, but seriously RIOT, its like you don't care about the people anymore yo...