Debt Collector

Debt Collector is a side quest in Fallout: New Vegas.

Detailed walkthrough
Talk to Francine Garret at the Atomic Wrangler, and ask if she needs any work done. She will inform you there are three individuals in Freeside that owe the casino caps. In total it will be 600 caps owed, and you will gain 150 caps if you return the caps to Francine (300 with a Speech or Barter check of 50). The three individuals are Grecks, Santiago, and Lady Jane. You can pay out of your own pocket if you wish.
 * Grecks is located behind the Old Mormon Fort. He will give you the money with either a Speech check or a punch to the face (through dialogue). A second Speech check of 40 or higher will net you additional caps, and a third of 60 will cause him to give you the clothes off his back (negative Karma).
 * Santiago is located behind the collapsed building opposite Mick & Ralph's. He will try to talk his way out of it, but revealing that there's a bounty on his head or punch him in the face will get him to pay up. He will give you more caps with a Speech check. If you have the Wang Dang Atomic Tango quest also active at the same time, you can convince him to work off his debt at the Atomic Wrangler, also completing the suave talker portion of that quest. Doing this, you'll only have to return to Francine with the 388 caps from the other 2, but will still get your full reward for collecting the debts (150 or 300 caps, depending on the earlier barter check).
 * Lady Jane is located to the right of The Strip North Gate. You can either get the money through a Speech Check of 40, a Barter check of 40, or the Lady Killer perk. With a Perception of 7 or higher, your character will be able to tell she is lying and get the caps. You could also ask for other things to help pay off the debt. Doing this results in her giving you 156 caps and 94 caps worth of sensor modules and cartons of cigarettes (neither killing or pickpocketing her at this stage of the quest will work. Doing either would result in you having to collect caps from her caravan). Failing that, she'll direct you to the caravan she lost in the Broc flower cave, good loot can be found if you venture further into the cave. You can also fail all checks and another option will show up for threatening her. She will ask you to tell the Garrets she's dead, to which you reply you don't like liars. Choosing this option will turn her hostile, allowing you to kill her and collect the 256 caps (she will have a bag of bottle caps on her corpse).
 * If you have entered this cave before receiving this quest the brahmin will not be in the cave.
 * The brahmin will not spawn until you agree to retrieve the debt this way.

Once those three are done, Francine will give you a fourth assignment. Her former collector, Caleb McCaffery, skipped town with a large sum of caps, and she wants him dead. His hat needs to be taken as proof.
 * Caleb is in the Strip, in the first section near the gate to the second. With a Speech check of 40, he'll give you his hat and the stolen caps. Otherwise, you'll need to kill him for it. Note that the entrance to the Strip will require that you have at least 2000 caps (not as payment, but merely checked against as a minimum necessary value), a passport, or pass a Science check of 80. Alternatively, you can simply use the monorail if you are good with the NCR and have not let it be destroyed in I Put a Spell on You.
 * On consoles, a major bug may render the game essentially unbeatable if you kill Caleb. See the Bugs section.

Bringing the hat back to Francine will finish the quest, earning you caps, and Freeside Fame Reputation.

Gallery
Schuldeneintreiber Coleccionista de Deudas Коллектор (квест)