@Stickystickysticky That is exactly what I am trying to figure out, because this unfinished page is just such an anomaly - yes, there are multiple and European-wide laws and regulations concerning data protection via electronic networks: in this case, the requirement for any entity which communicates via newsletter or regular e-mail must by law also feature a clear opt-out for any subscriber to that newsletter: the "Unsubscribe" button at the bottom of the communication, which must lead you to a link where you can get yourself off the subscription with a firm promise that you have, indeed, been unsubscribed from the list, no further ambiguity, no trouble or fuss.
In this case, we have a totally phantom site with a phantom newsletter with a phantom company still in the preliminary stages of getting consent to market its future products, and therefore not breaking the letter of the law, although it is very much breaking the law by playing fast and loose with people's data in a totally unaccountable manner. Unfortunately I have no proof of an actual data breach: it is all simply just thoroughly bad practice.
Who you complain to about any data breach, if you haven't got anywhere with the company in the first instance, is the government's Information Commissioner's Office, who deal with all aspects: I have to log off now, but here is the link to the site, and, specifically the Complaints Submission Page: it would be as well to know about this for the future: Make a complaint | ICO