You have muddled things up by requesting a cancellation when the order is probably on its way - a week seems like a long time, but the 4 days of the Easter weekend were not working days so your order is probably not even late yet.
Find the email you got from Ebay when you paid and check the latest estimated delivery date.
One day after that date, you should be able to open a case stating you have not received your item.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)