I have received email that there is a store credit that was applied to my account for several month every time I go to check I have no balance? Why would this be?

"After you request a refund, you'll receive an [email*] update" as to whether you have been granted a refund "within 48 hours." If your request is granted "the time it takes for the money to appear on your account or statement depends on the payment method." Refunds go back to the method used to make the payment originally.

- Store credit: 48 hours

- Mobile phone billing: Up to 60 days

- Other payment methods: Up to 30 days for it to appear on a statement.

*You can also sign into https://reportaproblem.apple.com to check if the status of your item is "Refunded".

From: How long refunds from the App Store or other Apple services take - https://support.apple.com/HT210904

If you need to contact Apple about this, click on this link --> https://support.apple.com/choose-country-region/media-services and choose a path that gets assistance from iTunes Store staff.