Capitalization of a name with the same characters cannot be changed

 Today as I was going to change my name back to its true form (NotAnt), I was blocked with "This profile name is not available." My current name is nOTaNT, the same characters, but with different capitalization. 
I figured this may have just been a visual glitch, but I was proven wrong when I still could not click the "Change Profile Name" button.

Help Me!!! I want to go back to my old name