Can't matchmake

Initially I was having trouble authenticating. I ran the hextech repair tool and flushed my DNS, and I managed to log in.

I queue up for norms, and I get in lobby. Everyone gets booted. I queue up again and accept a match, nothing happens and it kicks me out of queue. This happened multiple times in a row, and I can't seem to get past matchmaking. My internet connection was stable this entire time.

EDIT: I'm back to the authentication problem again.