Something is wrong with this app – Math. Review

I wonder if you discontinued service. I have subscribed this app for a while and I have been busy to login this app. I wanted to use this app, but only show the top part, which is “welcome to yourTeacher’s math app” , and does not show anything. I would like to have a refund unless you solve the issue. Thank you.
Review by Hanabananannanani on Math..