For the dutch its: https://www.autoriteitpersoonsgegevens.nl/een-tip-of-klacht-indienen-bij-de-ap
But to be honest I think its already on their radar since its also in the news here (some) but every bit helps (i think)
Like the topic says in the last paragraph “ Find your supervisory authority (just use google, for added irony) by searching for “Data Protection supervisory authority [the state you live in]”. but with state you should fill in your country.
Sorry didnt copy what i wrote. Some along the line of well what they are selling and to whom and pasted the url from this article in the box. Nothing to lengthy, so its not a bother to read, just the facts, as far as i know them that is. Keep it short and simple. You can also attach documents if you have any.