Report a bug of promotion

I was in bronze 1 to silver promotion and was playing my fourth game which I won. But what happened after my fourth game was that a notification came up and said I was in a new promotion, my record got clean up (2:2), so I will have to start it over for my promote game. You can check my match history, from December 19th the last 4 ranked games. Just thought this is a bug, so hope you guys can fix it, thank you!