the bad user is @LouisLsn
i refused to sell him something, this has been his reaction.
my advertisement was clear: "i want to sell my system as a whole and not just single modules"
initially i didn't even replied to him because my reasoning was already clear in my advertisement, but the next day he sent me another message, therefore i replied that i'm not interested in selling single modules but i'll get back to him if i'll remain with the 2 that he wants.
and here is when he started to lose his mind (if he ever had one).
in his mind i was the one "abusing" something, and not him abusing my patient with his unrequested messages, read wis words:
and one month later our conversation he texted me another unrequested message, in his mind he still was the one entitled to harass me right after i said NO to his askings:
if this system would have a "ban" button i would have already used on him, but there isn't.
and i did't even left a negative feedback on his page at time, but then yesterday someone popped up on Facebook, months later this episode asking me the same thing for the same modules and i think it is the same person because the nickname is pretty similar and the city of provenance is the same, i wouldn't be surprised if 6 months later he still hasn't found someone willing to sell something to him.
(EDIT: in the mean time i already sold what i had to sell and remained with just 3 modules on my offerings, added for context and before someone pops out in defense of this "seriuos buyer")