The strange thing that I find about these companies, whether in Spain
or not, is that I don't run across them.
Why is that? They never get in touch with me, unless they are the anonymous, telephoned, voices that I hang up on. One clue as to what those are is when the phone rings at the other end. That means that they are phoning whole groups of people at the same time.
The clues to hang up are there before they, even, get the first words out. Another one is that most of them do not know your name, which they should do and, also, that they introduce themselves, such as, "Hallo, I am John Brown, etc.
Their first task is to get a response from the called person so that they can get a conversation going. Most of the time, all they get from me is silence, until I identify their motives.
The people I know have a way of opening the call that shows familiarity with me and/or my family. Very few others get past.