You can re-initiate payment for your subscription by clicking on the "Settings" icon in the top right-hand corner of your account in the V1 portal and then on "My Portal Account" or in the top left-hand corner of the V2 portal on the menu and then on "Account". Here you will find the menu item "Orders".
Please choose the failed payment and click the "Pay" button. There you will also be asked to enter new payment details. If you go through the steps and initiate the payment again, the subscription will continue to run with the new payment method.
If this does not work, you will have to cancel the subscription and take out a new one.