Hi @Kmkelly Looks like your account was upgraded through Apple (iTunes). I would recommend verifying your payment information with them.
Please note: Since Apple has recently updated their operating systems, the following steps are for listeners who have updated to iOS 13. If you haven't updated to iOS 13 yet, please let me know and I can send over alternative steps.
Since you purchased your Pandora subscription through Apple from an iOS device, you can use the following steps to update the credit card associated with your Apple ID.
Here are the steps to do this on your iOS device:
From your iOS device Home Screen, tap on Settings.
Tap on your Apple IDat the top of the screen.
Next select Manage Payments.
From there you can edit or add all your payment methods.
To adda payment method press Add Payment Method.
To edita current payment method, tap on the card you have on file.