Cannot review apps in App Store nickname taken

I Have an iPad 4 with latest iOS update. I have purchased several Apps and tried to post reviews but it will not let me. I keep getting the same pop up message "Nickname taken please choose another". I have tried to post without entering a nickname but the send button is greyed out so I cannot send my review, I read another suggestion to not put a title or nickname but that doesn't work either. I have tried using my Apple ID but that doesn't work either. I have tried using this username (for posting here) but that also gives me "nickname taken...." I have also tried many different nickname combos and ones that no one could possibly have but STILL get nickname is taken.

How do I post a review in the APP store??? This is really frustrating!!