Insane Skill Differences In Normal Games

I've been playing Normal games to get to level 30, but in a few games I got completely destroyed. During the game I came to the conclusion that I was just playing poorly, but after the game in the end game lobby I learned that my opponents were level 3 s4 players (I am currently level 18 playing by myself). These players were playing with (probably) a friend that's new to the game, which would be fine if they weren't in these low level games. Just think about it. 1 level 12, 1 level 23, and 3 s4 players in a level 18-25 game completely outclassing you in skill. It's made winning my games and leveling a lot harder than it should be.