AFK Penalty

I understand that AFK people have to be penalized. but I mean. today my game glitched and I couldn't hear shit. the audio was disabled so i had to exit the game because It was really confusing to play without audio. obviously I got the ban for 5 minutes 5 games. but why don't we just get an hour or two ban. I mean i have to wait before every game?. I've gotten so many "You got reported messages" and I only afked like twice. the other time because my team was a bunch of dicks that were talking mad shit to me. and the other thing if i wait the 5 minutes. and then i exit the search. guess what. I have to wait that 5 minutes again. c'mon riot. at least make it flexible in the unranked mode.