Username can not be used?

I tried logging in the morning and kept receiving a username can not be used message. What do you mean I've been using it for about 2 weeks and have spent over 100 dollars in this game. I need this figured out soon. I have the same username as I do in haypi monsters 1, is this being a conflict.

Anyway. Staff please resolve this.

I've the same problem. Was online a minute ago, wanted to login again and then that message appeared...wtf???

EDIT: Seems fixed now, very strange.