Lost my promo because of a bug in champ select

Hello everyone. So I went to play the last ranked game of my promotion today. I had lost one and won another. After accepting the match, it took me to the champion selection screen. The problem was I couldn't do anything and saw nothing else but a message saying "retrieving data from server". I had this bug before, I think, a few times. It would stay like this forever. So I ended up having to close the window. This counted as a dodge from the game and therefore as a loss for my promotion.

Why does this happen and is there any chance I can get this last game for my promotion back?

Thank you all.