For over a year, Aruna had saved up the money her clients tipped her with at an Indian brothel she was sold in to, thinking could some day exchange the notes once she returned to her homeland, Bangladesh.
But soon after she was rescued from a brothel in the Indian city of Pune, she learned that the notes she had scraped together - 500 and 1000 rupee banknotes, totalling Rs10,000 - were rendered worthless in the wake of the ban Indian Prime Minister Narendra Modi had put on them in an effort to crack down on corruption.
So with the help of Rescue Foundation, the organisation that freed her, Aruna filed a grievance to PM Modi himself, via Twitter, reports Hindustan Times.
"I used to hide this money from the brothel keeper in my pants pocket as I wanted to take it home," Aruna wrote in a letter tweeted to Modi late on Tuesday from the Twitter handle of the Mumbai-based Rescue Foundation.
"I earned this money through much suffering. This money is precious. Please help me exchange it," she wrote.
Modi's shock currency move to withdraw its two highest banknotes aimed to bring billions of dollars of unaccounted wealth that people are hoarding, or "black money", into the mainstream economy and curb corruption.
But the demonetisation policy has left unintended victims like Aruna with nothing.
Previously employed as a garment worker in Bangladesh, Aruna was trafficked into India by a coworker with the familiar promise of a well-paying job. No sooner than she crossed the border, she was sold as a sex worker.
She worked at a brothel in Bangalore for a year and a half before being sold to another in Pune, where she was rescued a day after arriving, in December 2015.
In March this year, Bangladesh issued her a travel permit to return home.
Aruna is one of 19 trafficking survivors who on May 15 will board a train in Pune and travel about 1,800km to eastern India, where a police bus will take them across the border to Bangladesh.
But unless her money is exchanged, she will go home penniless.
"The money would lend some legitimacy to her absence from home. She will be able to tell her family that she was working in India," said Tanuja Pawar, assistant superintendent of the Rescue Foundation shelter in Pune where Aruna stays.
There has been no official response from the Prime Minister to Aruna's letter, Rescue Foundation officials said, and Modi's office did not immediately respond to requests for comment.
In the meantime, many people have come forward to give her money to take back home after her tweet.