During your purchase, you will be able to opt for any saved payment method you prefer for your 1st payment to be charged to. However, subsequent deductions for your 2nd and 3rd payments will be charged to your "Default" payment method instead.
For example: If you've opted to pay with "Credit Card (A)" during the point of purchase but "Credit Card (B)" has been tagged as your "Default" payment method, your 2nd and 3rd payments will be charged to "Credit Card (B)" instead.