(CNN) "It was like we won the lottery," Beth Rosser remembers. Her dad, Forest Jenkins, had just secured a $200,000 contract to work at the biggest prize in Atlantic City: Donald Trump's Taj Mahal.
His company installed toilet partitions -- not exactly glamorous, but important nonetheless. It was 1988, and a six-figure contract was huge.
"It was a big job. It was great. We were all excited," says Forest's son Steven Jenkins. Jenkins spent a month working at the Taj. "I had the fuzz from those carpets on the wheels of my dolly for months after that job."
But what seemed like a winning ticket soon turned into a nightmare when the paycheck never came.
"We weren't this big company," remembers Rosser, who now runs the company with her brother, Steven. "We didn't have tons of money in an account somewhere to cover things."
Jenkins says his dad, who built the company from nothing, nearly lost everything.
The Taj Mahal, the most expensive casino ever built in Atlantic City filed for bankruptcy in 1991, just two years after its glitzy grand opening. The bankruptcy meant companies like Triad Building Specialties didn't get paid.
After years of fighting through bankruptcy court, the Jenkins ended up with just 30 cents on the dollar. Their company was owed $231,000, according to the bankruptcy claim filed in the case. The Jenkins family received $70,000.
The Jenkins family realized they weren't alone. Dozens of contractors who had worked on the construction were also getting stiffed.
"It's 27 years later. I grit my teeth every time I see him on television blustering about what a wonderful businessman he is," Rosser says. "He stepped on a lot of people."
CNN reached out to the Trump campaign about each of the business deals mentioned in this story. Those calls went unanswered.
Nat Hyman also knows what it's like to lose money at the hands of Trump.
"When he's nice, he's very, very nice. And when he's nasty, he's immensely nasty. He is as rough as they get," says Hyman, who claims he spent years buried in litigation with Trump.
In 1996, Hyman was a young entrepreneur who thought he landed a great deal when he secured a kiosk inside the Trump Tower lobby for his costume jewelry company, Landau Jewelry. His nascent business flourished and, eventually, the jeweler was able to negotiate deals with Trump to open additional kiosks inside his Atlantic City casinos.
But then Hyman's success was stymied. He claims his kiosk inside Trump Tower was in a prime location, so Trump tried to force him out of the spot. Trump's lawyers sent letters citing "the poor quality of the merchandise" -- a claim Hyman says was unfounded.
When Hyman wouldn't move, he says Trump retaliated against him by canceling his leases for the Atlantic City casinos and burying him in legal paperwork.
"I think I spent over a million dollars in litigation with him," Hyman says.
Hyman eventually left Trump Tower after 14 years. Trump replaced the jeweler's kiosk with his own merchandise that bore his name.
If he had to do it all over again, Hyman says he would have never gone into business with the real-estate tycoon.
"I tried to stand up to him everywhere I could but it's exhausting, and it's silly. To him, it's a sport. To him, it's fun."
On the campaign trail in June, Trump promised the crowd that his business experience would create thousands of new jobs.
"We will make it very, very good for our companies, for our small business and for people that want to survive and do well in our country," Trump pledged.
But Paul Friel says his dad's small business went under at the hands of the billionaire.
The Edward J. Friel Company built cabinets for Trump's first Atlantic City casino in the early 1980s. The company was awarded a $400,000 contract to build cabinets for the slot machines at Trump Plaza.
After the work was completed and approved by the general contractor, Friel expected a payment of $84,000, which would have covered the final expenses and all of the profit. But Friel says Trump bought out the construction contract from the general contractor, Perini Corporation, and then refused to make the payment.
It was a shock to his father, Friel remembers.
"We had already worked for three (general contractors), and every single one of them lived up to their word until Donald Trump came to Atlantic City," Friel says.
Friel's father tried to recoup the money he was owed but eventually gave up. Friel believes Trump used his enormous influence to block his father's company from working on any future Atlantic City projects.
"I think it surprised him the most that Donald Trump had blackballed him ... even though we had an excellent name in Atlantic City," Friel says.
After struggling to stay afloat, the Edward J. Friel Company filed for bankruptcy several years later.
"He was devastated. The fact that we had seen such a huge future in Atlantic City for his business that all of a sudden because of one deal ... his business in Atlantic City was done," Friel says.
At the Republican National Convention in Cleveland Trump promised to prosperity for America, saying: "I have made billions of dollars in business making deals. Now I'm going to make our country rich again."
Friel says he's speaking out on behalf of his father, who died in 2006.
"He would say, 'Paul, do this for us...let the country know what kind of man this is."