I have received an odd email for an iTunes card purchase which has been sent to: blarkart403@xcodes.net? Not me??? I have changed my password but when I log in it tells me my Apple ID is being used at another location? What should I do?

You are sure that it’s a genuine email from Apple and not a phishing attempt trying to get your account and payment details ?

Phishing and similar emails : Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support

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

Goanna,

When you "changed my password several times today," did you do it the official way at appleid.apple.com, or did you follow a link in that questionable email? If the latter, you may have inadvertently revealed your credentials to a fake site. Please see this guide:

If you think your Apple ID has been compromised - Apple Support

Anna,

If you are pretty sure you didn't give your password to a fake site, you are probably OK. The person near Canberra might be a hacker, or they might just be a confused person trying an incorrect Apple ID.

However, please look in the article that I linked, and be very vigilant for the symptoms listed in the section "How Do I Know if My Apple ID was Compromised." If there is a real sign of trouble, continue to the section after.