Try using a different browser and incognito mode. Also clear your cache and cookies then reboot. If you still need assistance then submit a ticket by clicking on the question mark on the bottom right.
Lorena from Public Mobile here. If you have problems with logging into your Self Serve account, please check with SIMon here --> SIMon help <--.
I can also advise you to clear your cookies&caches for the used browser. If it still doesn't work, try with another browser and pay attention when you are writing your email address. You can also try the forgot password option.
Public Mobile Moderator Team