turrets and all their stupidity

sorry if the title is a bit much but it is long overdue that turrets need to seriously change how they work or they seriously need fixed.. just now i died under turret to a vi ult and guess what? turret doesnt target the vi.. same stuff has happened repeatedly with many other champions.

the only thing i know is that the turrets refuse to do anything aside from target minions when im the one getting hit while both the enemy champion and my champion are both directly under turret.. literally i was standing so close to it that if i did an emote i would have hit my champions head on the turret.

however when i start attacking people under turret even if i kill them before i get aggro, as in only one attack under turret kills them, as it seems is what stops my turrets from targeting the enemy champions, i get turret aggro instantly.. or is it that champions that basically "jump" into turret range are still counted as outside turret range until their skill is over with(meaning damage done inside turret range due to that skill is counted as outside turret range?) making the turret think oh that champ didnt touch my team?... 3 games in a row now that this has happened to me and im about ready to quit once again due to the many game breaking bugs..