League of Legends Client Bug

Me and my friend finished a game of ARURF and we wanted to play flex with another friend. We couldn't start the queue so we restarted our client. When we loaded back into the League Client, it started a match that we never started. Now we left and when our friend checks what match are we in it just says that we are playing the champions from ARURF, and its not saying what mode. When i exit out of the "match"(it's just a black screen) it just says reconnect. If anybody knows how to fix this problem please write it down. Keep in mind that its for me and my friend. We both have the same problem.