Had the same problem when trying to pay with iDEAL at www.myposter.nl
Sent them an email. This was their response:
Bedankt voor de vraag.
Het is helaas niet mogelijk alle banken naar wens toe te voegen. We kunnen daarom helaas niet an uw verzoek voldoen en vragen om een andere betaaloptie te kiezen.
Met vriendelijke groet,
I also contacted Bunq private matters on this. In the past I remember Bunq would contact these companies because of iDEAL guidelines indeed.
I now got the response from .org Bunq support employee #1 and an ‘escalated’ Bunq support employee that they cannot do anything about it. They suggested me to use my Debit Card instead.
I understand ignorance at these example companies not obeying iDEAL guidelines.
However, I’m a bit disappointed in the latest Bunq stance on not acting towards these companies.
I propose Bunq would set up a default email message they can send to the relevant company department that insists a bit ‘stronger’ they take action and add Bunq to the list of iDEAL banks.