Useless app

Stupid Stupid app.i wonder who came up with this idea..I just changed a phone and I want to log in my account and they telling me a device is already linked..what kind of Stupid nonsense is that. Even with big banks you can log in any device as long as you know your log in details..now I unstalled the app from my old phone thinking it'll work on my new phone but nothing. I installed it again now it keeps loading. This is annoying. I texted them on whatsapp and they haven't rep****. I called them they not answering. I hate hate this app..now I must go hungry because of their incompetence. Useless ..