Credit/Debit Card Order
A refund for a cancelled order which was originally made using a credit or debit card may take up to five days to show on your credit/bank statement but typically appears in 24-48 hours depending on your bank.
PayPal using your Credit/Debit Card
Refunds to PayPal are instant and the funds are instantly removed from our account back to yours. If you used your credit/debit card and the funds are not in your PayPal balance, it may take additional time to appear on your card statement.
According to this PayPal article, it may take up to 30 days: https://www.paypal.com/selfhelp/article/FAQ1083