Why are there Bots in my regular matches??

This is NOT a joke and I am not insulting anyone by comparing their playstyles with bots. Here we go :/

I have done over 10+ARAM matches and 1 Co.op vs Al match today and every game I notice that I get paired up with a bot teammate that does nothing but autoattack and stand in front of our enemies, giving them an easy kill. I noticed this strange behavior on one of our enemies' ally too and they are willing to report it. This is a pretty HUGE bug and needs to be fixed :/ I've even had 1 ARAM match where my team gets the bot teammate and the enemies do not -.- As a result we lost because the bot user fed everyone on the other team and went 1/20. I'm sorry I cant explain this properly enough but this bug has pissed me off bc it ruined ALL of my matches. Please fix this ASAP so I can play safely again :l