A refund is only instant if they already have money in Paypal. If not, it will take a few days. If you don't see a refund pending in your Paypal account, that means the seller never initiated the refund.
yea I just got refunded on paypal because I bought an Idmax off ebay and the guy dropped and broke it before shipping, it took almost a week for the refund to process but I did get it back. It should show up in the pending transactions thing on paypal