afk'ers in ranked

hello, AFK'ers in ranked, everyone has it. But why isn't there a system if you've got like a afk'er or more before the 20th minute or so, that you don't lose the normal amount of LP or just no LP. And also if you have 2 AFK'ers from the start of the match than you don't lose LP why not already at 1? if the enemy team are normal persons they should always win, right? Riot please make a better system for this because afk'ers are so frustrating...

hope this will be fixed somehow and soon....