Why are a bunch of solos matched against a 5 man team?

^Why does this happen? I was having fun throughout the game when I noticed that it took 5 people to kill me. I also noticed that kennen tped and ulted to kill me and only me when I was already getting killed by 4 people. After that gang bang I proceeded to ask why it took 5 people to kill me and then they replied, "It's a team game." When they typed in chat I noticed that they had the same club tag. THEN I proceeded to ask them why we are going against a 5 man and they said "You are a duo aren't you?" I replied and said no i'm a solo and so did the rest of my team. After we figured that out I decided to surrender, because we were already losing and I was left with a bad taste in my mouth knowing I was going against a 5 man premade. I am in no way trying to blame this on the enemy team, I'm just trying to figure out why I, and others, are getting paired against 5 man premades when we are all solos. I didn't mean to be a whinny baby, but its not like it only happens to me it happens to alot of people. This has probably been said many times about dynamic queue, expecially from people that have been playing the game since before dynamic queue.