Have you had an email from Ebay saying the order has been cancelled and your refund is being processed?
If you have, then the money will be on its way.
If you haven't had an email, it is because the seller has not started the process.
I find refunds to Paypal are more or less instant.
Refunds to banks can take 5 days.
If you paid by credit card, it can take quite a lot longer for the amount to show on your statement as a credit.
So, have you had an email saying the refund is being processed?
How did you pay?
"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)