While I’m not sure what the old list contained, I know that Nigeria was removed several months ago. You can refer to the latest list of 27 countries so you know what you can call to in the FAQ list of the following link:
https://www.koodomobile.com/en/services/pickyourperk?srsltid=AfmBOordn3qAHNaZmStBEjBdvFcnEy9TgZ8GmECERQOj2oI2nQDluazv
As for lack of support and transparency, what lack of support are you referring to? I assume it’s related to not being informed that the list has changed? I’m not sure it’s realistic to outline every single perk or add-on or plan offerings that get changed every single time.