A Dallas restaurant owner has joined a chorus of businesses across the country that allege the restaurant review company Yelp is trying to strong-arm them into purchasing advertising help, or else.

"At its peak, maybe four a day," said Bob Sinnott of the personal calls he began receiving about five months ago, along with calls to other members of his management staff at his restaurant.

Sinott owns Toasted, located in the Lower Greenville neighborhood of Dallas.

"You feel it's harassment?" WFAA asked him.

"For sure," he said.

Sinnott said the company wanted him to pay a monthly fee to help him manage his Yelp page, which in its basic form is essentially free. It's a platform where restaurant reviewers and regular diners can submit reviews of an individual establishment.

Sinnott said he repeatedly turned down the offers from Yelp. That's when he said his positive Yelp reviews started to disappear and bad ones started to move up.

"At the point where I finally said, 'I am not going to do this,' my review average dropped below four for the first time, and I noticed a chunk of reviews had been moved off," he aid. "Clearly because I was not considering to pay them. "

"So you think that's their retribution for not paying?" WFAA asked.

"100 percent," he said.

This is a complaint that Yelp has defended itself against many times before. In fact, its response by email was immediate, disputing any allegation that they pressure business owners for money.

In a statement to WFAA, a Yelp spokesperson said that "any claims that Yelp manipulates reviews for money, or that advertisers are treated any differently than non-advertisers, are completely false and have been repeatedly dismissed by courts of law, thoroughly researched and disproven by academic study, and investigated by government regulators, including the FTC, who closed a nearly two-year investigation without taking action."

But Yelp is also getting ready to defend itself against an entire documentary on these same allegations. The documentary is called "Billion Dollar Bully" and details what many restaurant owners have been trying to prove in court.

"If the mafia had done what Yelp is doing, they'd be thriving in every county and every jurisdiction in the United States by doing it over the internet," said attorney Lawrence Murray in a trailer for the documentary.

Sinnott said a Yelp representative told him that any changes to the Yelp page for his restaurant Toasted are purely coincidental and linked to the software algorithm the website uses. He said he remains convinced the changes were intentional.

"I'm just mad enough that I'm going to speak out about it because it was a direct result of me saying, 'I am not going to pay you a monthly fee' and then right then the reviews were manipulated," he said.

Reviews he said he'll try to ignore. And, with Yelp's help or not, he'll continue to work to keep his restaurant thriving.