Not Being Able to Pick a Champion

I was getting ready for a ranked game and clicked on amumu, the game gave me a pop-up saying that it was retrieving connection and then the box went away and i still wasnt amumu. I then proceeded to click on amumu multiple time and the timer went to 0 without me picking a champ. It stuck to where it was my turn to pick for five minutes and nothing happened so i left. When i left, i came back to a 25 minute ban and i lost lp for an incident that i couldn't have helped. rito pls