If the seller won't accept your cancellation and send a refund, you must wait 7 days then open a case through Ebay to say you have not received your item.
Follow the process correctly and you will get a refund.
"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)