Can't Login

I downloaded the app, filled out my details and it registered fine. I transferred money in and while waiting for it to appear it logged me out and now I cannot login no matter what I do. I restart my phone, reinstall the app, change my internet from wifi to data but every single time I open the app it treats me as if I am a new user. If I fill out my details again it just takes me back to the beginning to restart the sign up process. Why is this happening?