Two losses on competitive without entering any game

Yesterday I have been banned and I don´t know why. There were two times that I was in training mode, waiting for competitive game, and when I got the message that game was found it remained on the menu without entering any game. Then I saw the option REJOIN Game but even when I clicked on it it didn´t work. How can I rejoin a game I didn´t start ?¿ Now I see I have two losses in Competitive which I never played… Matchmaking system is broken because of which I had a losing streak of 0-14, playing against a Diamond healer (in bronze5) and playing several times against the same team that were overplaying us and now this.