You can update your account's payment method at any time. The next charge will use the new method.
Go to diio settings → Billing.
Click "Add new card" (if you don't have one) or "Update card" (if you want to replace the current one). You can only have one card on file.
Enter the card details: number, expiration date and security code. Visa, Mastercard and Amex are accepted.
Confirm. The next charge will be applied to the new method.