When I attempt to login, GGPoker says my account does not exist
Typically this prompts indicates that you're registered with another skin such as Natural8, Optibet, BestPoker, GGPokerSITE and GGPokerOK.
Provided you are directly registered with GGPoker, please contact help@ggpoker.com including a screengrab of your app's home screen with the logo displayed.