Can't you message the green person on your site to say you made a mistake, when inputting it?
I might be wrong but I thought they cannot change the birthday itself, only the age if the user already passed that ig week? :o
If so being able to change the birthday for money could be a nice option to have. Maybe the user changed their mind, or they want to redo their character with a new birthday. :D
But if they can then yeah just ask them for help. XD
Customer support service by UserEcho