BABYLON, N.Y. (CBSNewYork) – Online reviews can make or break a business.

But what happens when a bad review is inaccurate and goes viral?

That’s what happened to a dress shop owner on Long Island who is now speaking out to set the record straight, and to warn other merchants.

Paula Evangelista, who owns Omnibus Fashions told CBS2’s Carolyn Gusoff she used to like reading glowing store reviews online, until one review recently popped up: Scathing and, she claims, patently false.

“I was horrified. I’m reading it – none of it was true,” said Evangelista.

The reviewer claimed a customer was mistreated at Omnibus Fashions and denied a credit on a new dress that no longer fit her after a mastectomy.

0928comment Mistaken, Negative Review Goes Viral, Causing Big Trouble For Long Island Business

(Credit: CBS2)

“Everyone we know will never step foot in there again,” the reviewer wrote. “Shame on you Omnibus.”

“The whole post was 100 percent inaccurate,” Evangelista said.

The false tale spread quickly.

“I saw it on Facebook… Yelp… Google,” she told Gusoff.

The comments also spread quickly, shared over and over again, calling Omnibus “corporate thieves,” and saying “don’t shop there” and accusing them having “no compassion.”

“That I was a money-grubbing store. And that I was not sympathetic to someone who had breast cancer,” Evangelista said.

Gusoff spoke by phone to the customer who confirmed her friend’s post got it all wrong.

“I feel terrible, I feel like it’s my fault,” the customer told Gusoff.

After cancer surgery she came in to buy a second dress but never asked for a credit on the first dress.

“If I could erase everyone’s [comments] I would do that. I don’t know what else to do,” the customer said.

But the shared post now lives on in cyberspace.

What years ago may have been an inaccurate rumor spread by word of mouth can no go viral instantly. That’s why businesses are advised to act quickly when there’s a reputation crisis.

Hilary Topper of HJMT Public Relations has some tips on what business owners should do: Set up a Google alert so that you know when your business is reviewed. If you’re going viral for all the wrong reasons, Topper says you should respond unemotionally in equally visible posts.

“It’s really important that positive reviews are posted about your business so that the negative reviews drop down,” Topper said.

Omnibus Fashions has an apology from the woman who first posted, which says “My understanding of the situation was incorrect. I had no idea of the magnitude my post would create.”

The apology has not gotten the same number of shares.

A spokesperson for Yelp tells CBS2:

“Business owners and Yelp users both have the ability to flag a review if they believe it violates Yelp’s Terms of Service. All flagged reviews are assessed by our User Operations team and reviews that are found to be in violation of our TOS are completely removed from the site and no longer visible.”