I'm held hostage in my promos...

I literally just won my last promo game, nexus exploded and all

Then suddenly, I literally cannot leave. No stat screen and I'm stuck staring at a black screen. Attempting to leave forces me to the reconnect screen

The match showed up in my history, I HAVE PROOF that I won that damn game and Riot's denying me my promotion

http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1915768865/50926790?tab=overview