Why am I constantly being put against level 30s when I'm only level 24?

Matchmaking in this game is a mess, not just for ranked but for normals as well. I'm only level 24 but I am always put against teams of at least 1-3 level 30s, usually rank silver/low gold. Of course my team gets absolutely destroyed and makes us have no fun whatsoever. Not only that but these teams we face taunt us endlessly and are toxic in all-chat.

Riot please fix your matchmaking. Its horrible.