If you placed it on the credit card, call the credit card company, explain that you have cancelled the order and stop the payment.
Email them, keep a copy for yourself, with all of the information and let them know that you are cancelling your order, and have cancelled the payment on your credit card. And keep calling

Eventually you might get someone to tell in person. I would also write them a letter with delivery and signature confirmation cancelling the order, and overnight or priority mail it, that way you have confirmed receipt of the cancellation.
You can even fax it to them

FAX (626)813-3810
As long as you submit the cancellation, and if they product comes to you, send it back, they shouldnt be able to charge you, and your credit card company should work with you there.