Fuera de servicio literally means "out of service." It's an interesting phrase because it's commonly used for inanimate objects like machines or phones, but here it's applied to people.
In the song, El Fantasma uses this phrase to describe fair-weather friends who were only around when he had money or could provide them with something. When he was struggling and "poor," these friends were suddenly "out of service," implying they were unavailable or unwilling to help, highlighting their disloyalty.
Ever had a friend who only calls when they need something? In "Fuera De Servicio," which means "Out of Service," El Fantasma sings a sarcastic message to all the so-called friends and family who disappeared when he was struggling. He tells them not to worry because he's doing well now, his "good luck has returned," and they're welcome to say hello again.
Throughout the song, he ironically makes excuses for them, saying he knows they were just "busy" when they didn't answer his calls or pay back the money he lent them. The real message is clear: when he was poor, their phones were always "out of service," but now that he's successful, they're suddenly available again. It's a powerful song about fake friends and the loyalty that money can't buy.