Your payment method is actually handled and processed through your Google Android Playstore or Apple Appstore accounts. If you'd like to update them, here is how!
On your Android phone or tablet, open the Google Play Store app .
Tap Menu Payment methods More payment settings.
If asked, sign in to pay.google.com.
Under the payment method you want to edit, tap Edit.
Make your updates.
Follow this link :)
Use this link to log into your account and then tap on "Payment" below