"Barrio Palermo" is almost like someone from NYC saying "In the Manhattan area".
There are locutorios on nearly every street with a business in this city. Get outside, walk down the sidewalk, and look for the red locutorio sign that has an icon of a "mouse" on the locutorio sign.
If that doesn't work, look in the doors that say "INTERNET" on the front window and have about a kazillion computers inside.
Good luck.