Sprint App

Hey! I'm writing this because as of the past 3 weeks my Sprint App is no longer working. Ever since I added a second phone to my account it doesn't allow me to view my bill, or even edit my profile anywhere (website or app). The My Sprint app on both devices only show the current device and says to view billing I need to be on the owners account but I am the owner for the account and when I try and create a new account to make me the owner it doesn't work. I still don't understand why I can't just be a T-Mobile customer instead of Sprint by T-Mobile because nothing seems to be working anymore.