Refund Help!

Description

Hello, I am from the U.K and I am trying to refund a payment made to me through a purchase on eBay (also from the U.K). When I first tried to refund the payment, I was shown an error that the refund could not be completed as I had a PayPal balance of zero. After hours of trying (and ultimately failing) to add money to my balance from my personal bank account(s), I tried to refund the payment again and this time it went through (even with zero PayPal balance). The refund then appeared on my activity with a transaction ID. It says that the refund is funded with money from a bank card that I have linked to my PayPal. However, the refund has been pending since 17th of December and no money has come out of the bank account. Does anyone know if this is a normal? Should I wait a bit longer or there a problem with the transaction? Many Thanks