Charges on Credit Card, but Apple says I never paid that amount

I see an Apple bill for a specific amount. I do not recognize. I go down the maze of apple support, only to find that this charge has never been made by me.

So now what? How do I stop this illegal charge from happening again? I will report this to my credit card company this time, but what do I do if the charge is recurring, even when apple says that no such charge is associated with my account?

HELP!

[Edited by Moderator]