iPhone Battery Refund to Old Credit Card

Hey guys,

So I'm happy to say I was eligible for the $50 refund in replacing my iPhone 6 battery. However, the e-mail letting me know I'm being refunded says that they will be crediting the credit card used to purchase the new battery. This being over a year ago - is a now defunct credit card. The emails came from a "noreply" address and considering this is a rare instance there's no "refund department" to call.

What happens if the refund never reaches me because it's being sent off into the ether of dead credit cards?