Uit eigen beweging
Algemeenbol.com changes the payment method to "pay later" in their GUI, which is tricky to detect. Then if you miss their email (in my case they go to a separate folder) you will start paying 3,50 euros per notification. I spotted this by chance today and discovered already 6 or 7 such outstanding fees. That was absolutely unnecessary if I would notice the change in payments right away. To me, it sounds like a very bad GUI/UX. Plus, this is already a long-lasting issue, and if they do not fix it makes me think about the reasons behind it.
KlantenserviceOn top of that, customer support is very rude and declines to talk about such issues - they say they do not understand what is the problem.