Do not delete your app at all. I had problems logging in a few days ago and my usual go-to to fix bugs to make sure it isn't client side is to delete the app and redownload. However if you do that here you can kiss any progress you made goodbye. If you didn't copy down you account info and create a transfer password, you account is now lost in the void. Bandainamco says on their support page they can not recover this data. All the progress I made and my 200k+ power account is now lost.