User blog comment:Ishimura Elite/So I Can't Play Infinity Anymore/@comment-1824272-20161123135432

Mission Completion Rank is a measure of your ability to play matches all the way through to the results screen. It goes from S to C, I believe, where S rank puts no restrictions on your account and C rank almost completely forbids you from playing the game.

This is not the first time you've complained about an internet problem here. On your previous blog post, one of your "gripes with Infinity" - namely #3 - was a symptom of poor internet connection. So, to hear that the game has dropped you down to Match Completion Rank C is not a surprise at all.

You need a better internet connection in order to play the game, because players with poor connections are prone to ruining matches for everyone else. Match Completion Rank is not designed to annoy you, it's designed to protect the rest of us from your internet.