Hello and sorry you're having problems.
Unfortunately we cannot change your billing info- that is something you must do yourself.
To change any CC information, you need to update your Amazon "One Click Payments" credit or debit card info from a PC at the link below:
If you need further assistance let me know. Please do not forget to click the 5 STAR RATING, at the top of the page for my efforts. It is my livelihood and you can follow up at any time if needed.
Let me know if you need further assistance once you see my reply.