Match making

Why does riot still refuse to actually fix balancing, because im experience horrible matchmaking, the games are not even playable, im an adequate player but im getting 2 shotted 4 mins into the game, the enemy team are doing damage 4 mins into the game that they shouldn't have tell mid game around 20-25 mins in, yes im using a normal rune and master page. i looked at their states in game and they are the same as mine yet they hit me twice i die, well in turn i hit them 5-6x doesn't even scratch their health. So something seriously wrong is going on with my match's