We had a warning from The Pokemon Company recently, but now the ill-fated Pokemon Rumble Rush is finally lost to the either. The game is now dead as a dodo. You can't log in anymore as all the servers are shut down for good. You can't download it either as the game has been removed from the iOS marketplace as well. So yeah, total and complete oblivion for this one.
All that remains from the game now lies in the memories that will live on indefinitely. Oh well, time to move to a different live service game, I guess.