hmm one thing i ran into today was a shop system.
they mixed prepaid payments with postpaid payments. or in other words -> if you want to use a voucher you need to fill in your credit card.
But everything you do not "use" will remain on your "account" but you can not use it unless you use your credit card ....
Hate those things they make me so mad... because obviously they implemented it just half-ass and that is something I hate even more ... checklist like programming ... now I have a voucher and still need a credit card ... this is just plain stupid ...