Inactive payment method Billie listed on form

[rvdsteege]

From customer:

An additional payment method has been added to our donation page: Billie. I assume this is due to an update. We do not have this payment option enabled. Can you tell me how to remove the method from the form?

I was able to reproduce the issue with the built-in forms, where Billie is listed even though it is not available nor active for the Mollie account. I suspect this has to do with Billie being available for German organizations only and asked Mollie about this (Discord):

I don't see Billie listed in the response of https://api.mollie.com/v2/methods/all. Is this method only included in the response for German users?

Internal Help Scout ticket: https://secure.helpscout.net/conversation/2344860912/26086

[rvdsteege]

I've received confirmation from Mollie:

Hi Reüel! Indeed, this method can only be used by German users. As the list all methods shows all payment methods that Mollie offers and can be activated by the Organization, Billie will not be included in the response in case of a non-German org.

The documentation at https://docs.mollie.com/reference/v2/methods-api/list-all-methods tells the same:

List all payment methods Retrieve all payment methods that Mollie offers and can be activated by the Organization.

Therefore, it's better if we deactivate all Mollie methods by default.

https://github.com/pronamic/wp-pronamic-pay-mollie/blob/25456829ebe00878d88cc82d67b3ee35f01d72de/src/Gateway.php#L258-L304