How to change payment method with new credit card details. Not able to change current one as card has expired. Pl help

I want to change my payment method with new credit card information as current credit card has expired. But when I try to change payment method , returns your payment method is not valid or allowed and continues to prompt to change the same. But when I try to update with whew credit card number, it doesn't accept and continue to refuse the payment method.

This problem is not allowing me to purchase of any kind either paid or even free as well. Doesn't allow to even purchase free books even

Please help to solve the issue

Thanks

Dpvora

India