Hello! Thank you for your question. I will be assisting you today.I'm sorry about the issue. Can you please re-edit (delete/re-add) your card details at the website below first?https://wallet.google.com/manage/#paymentMethods:If needed, please try with another card, if you have.
By the way, are you able to buy an ebook at the website below?
https://play.google.com/store/booksPlease let me know if there is still any issue. You can click on the Reply to Expert tab below and reply back to me, so I can help further as needed. Thank you very much.