You can modify your payment method at any time through your billing management. If you're already a QuestionScout Pro user, your billing page will look something like this:
In order to change your payment method, you need to click the Edit button next to Payment Method.
Afterwards, you will be redirected to a page where you can select whether you'd like to pay automatically using Credit Cards or manually using Credit Card, Bancontact, EPS, Giropay, iDEAL or SOFORT. Your next invoice will be paid using your newly selected payment method.