Security Question Prompt in iStore when making purchases

When attempting to make a purchase for my ipod, I am repeatedly prompted to create 3 security questions to confirm my identity. ITunes provides sample questions and asks me to select the question and provide the security response -- which I do. When I click submit, I receive a message that states an error has occurred and it cannot process my request. It then makes me cancel the transaction thereby preventing my purchase from going through.

This has been happing for a couple months now and I am still unable to make purchases. The same thing happens each attempt. I have tried everything I know how to do to update my account with security info, etc. but with no resolution.

Any help is appreciated! Thank you.