I have a suspect billing from "Apple Store" . I presume that this isn't Apple?

Correct, it's not from Apple, it's a phishing email - you could forward it to Apple : reportphishing@apple.com , and then delete it.

Phishing and similar emails : Phishing & Other Suspicious Emails

Genuine iTunes emails : Identifying legitimate emails from the iTunes Store - Apple Support

Correct. The address does not belong to apple. You can log in to http://reportaproblem.apple.com and verify any purchases made on your account I the last 90 days. If there is anything you don't recognize, you cna report it there as well.

As far as the email is concerned, you can send it to Apple for evaluation at reportphishing@apple.com:

http://www.apple.com/legal/more-resources/phishing/