Have you tried contacting iTunes support and asking them why it's appearing and how to resolve it ? They are the only people who can definitely tell you why you are getting the message : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page,
Yes I did. but still they dont know much. i just provide more information to them and i'm still waiting for the reply....
one thing.. i register a new account and use itune giftcard it in... i could purchase the inapp... after that i decided to buy more itune card. then after i redeemed it, i can't buy it again just like when i use my cc with my old account. it keep asking me to contact the itune support/ = ="