You need to go to Change/Update Payment Method. You'll be able to select Crysta that way. It really isn't that difficult. Could they put a "Pay with Crysta" button on the front page? Sure...but they're protecting you by preventing you from using/registering multiple payment methods at once. Imagine paying your monthly sub with crysta and forgetting you still had a recurring credit card payment set up and getting another charge for the monthly recurrence.