I payed a subscription with Apple Pay and I got it refunded but where would the money go to because my balance is £0.00 on my Apple account

See the following from Check the status of a refund for apps or content that you bought from Apple - Apple Support

When will I get the money back?

If your refund is approved, the funds are applied to the same payment method that you used to buy the item. Here's how long it takes for a refund to appear on your account or statement:

Store credit—It might take up to 48 hours to see the refund in your Apple Account balance.

Mobile phone billing—It might take up to 60 days for the statement to show the refund. Processing time might be affected by your carrier. You can contact your carrier for an update.

All other payment methods—It might take up to 30 days for the statement to show the refund. If you don't see the refund after 30 days, contact your financial institution.

sorry, but the only options I know of are to contact the bank and Apple Support. There is a Get Support link at the top right of this page.

I'm already more than 30days but not received yet, texting Apple support 2 times, asked to contact the institution. I have checked with the bank, said haven't received and asked back contact the one who gave refund. So confusing and I don't know where I have to put this issue?