Hi matthewdilks
Welcome to the Apple Community
Seems Apple processed your refund ok, and the Apple Card issuer would need to process it.
If you wish, you can scroll down on the webpage below to see all the refund details:
Returns & Refunds - Shopping
Eg says:
"If you canceled a pickup item, and you were billed for it, we initiate your refund immediately after you submit your cancellation request. The way your refund is processed depends on your original payment method:
If you paid by credit or debit card, refunds will be sent to the card-issuing bank within five business days of receipt of the returned item or cancellation request. Please contact the card-issuing bank with questions about when the credit will be posted to your account".
If you want more precise details, seems you might need to chat with an Apple Card Specialist at Goldman Sachs.
There is an Apple Card Support Website online, with various links:
Apple Card - Official Apple Support
All the best :-)