rain currently offers credit or debit card payments. Please ensure that 3D secure is activated on your card. You can manage this with your bank.
There are 3 payment date options. The 1st, 15th or 25th of every month. Your card will be debited on the payment date which you have chosen. By default, your payment date will be set to the 1st. You can change this by simply logging into my rain under my account.