Look in the top left corner when you login to your account you'll see belowAvailable Funds: $0.00Amount Due: $00.00Payment Due Date: Jan 00, 2018Hope that helps
Happens to me on occasions and my phone (S8 Plus) was directly from Samsung, previously re-start fixes the problem but lately I removed the SIM and cleaned it with and pencil eraser. Haven’t seen the problem reoccur.