For the better part of the last few years, hedge fund manager Bill Ackman has been embroiled in a war of words and money with Herbalife, a multilevel marketing company.

Now, the activist investor's case against Herbalife is being featured on the big screen, but viewers shouldn't expect a Hollywood ending. "Betting on Zero," a new documentary that debuted this week at the Tribeca Film Festival, chronicles Ackman's crusade against the company — which has done little to dent its stock or get regulators to take the billionaire's side.

Although his numerous broadsides against the company have yet to take effect, including a $1 billion bet against Herbalife's stock, Ackman continues to insist the company is little more than a scheme that harms those involved in selling its product.

"The real story are the people being harmed," who are overwhelmingly lower-income workers and immigrants who are Herbalife's foot soldiers, Ackman told CNBC this week, as he appeared on the red carpet of the Tribeca Film Festival.

"They sell people on a false business opportunity and they seduce a group of aspiring people that came to this country to pursue the American dream," he added. "They invest three thousand, five thousand, fifty thousand, a hundred thousand dollars" trying to move up the ladder, but ultimately lose money, Ackman added.

"They lose everything," Ackman said, calling Herbalife's system a "horrible way to take advantage of people [and] ruins dreams and aspirations."

Herbalife has repeatedly and forcefully rebutted those claims, which served as the basis for a brutal on-air skirmish between Ackman and investor Carl Icahn. In 2013, the two billionaires famously sparred in a CNBC segment, in which Icahn branded Ackman a "liar" and a "crybaby." The two later publicly reconciled, and Icahn remains Herbalife's biggest individual stockholder.

The fight against Herbalife "became a Wall Street story, a Bill Ackman, Carl Icahn story," Ackman told CNBC. Herbalife's workers "came to America to pursue the American dream, and they ... got ripped off ... by a pyramid scheme and they were afraid to complain."

In a statement to CNBC on Friday, Herbalife blasted "Betting on Zero" as an "infomercial for Bill Ackman's failing portfolio." The company claimed that the movie failed to include commentary from "any of our more than 4 million current members," and contended that Ackman and director Ted Braun have a decadeslong relationship.

Meanwhile, government investigators eventually cleared the company of any claims of being fraudulent. Probes by the FBI and U.S. attorney's office failed to find sufficient evidence against the company, while also clearing Ackman's closed-end fund, Pershing Square, against claims of stock manipulation. Ackman insisted that his sole concern was for those who may have been harmed by Herbalife, and pledged to donate any profit from the trade to those affected.

"Look I'm an investor, I'm investing others peoples' money. You know we made an investment on which we expected to make a profit on the basis of the facts. The facts are it's a pyramid scheme, we thought the government would do the right thing … [and] I didn't want to personally benefit from this." He added that he has pledged $75 million in various philanthropic donations to a mix of scholarships and investments in the Latino community.

In an interview with CNBC, Braun insisted that "Betting on Zero" was "as balanced a film as I could make. There were contradictions on both sides, I tried to present them as fully as I could."

— CNBC's Jacob Pramuk contributed to this article.