DENVER -- Families from around the country, who were looking for a Colorado vacation, turned to 3C's RV Rental. Now, many of them say they are out hundreds or even thousands of dollars because the company has not returned their deposits.

"Have you guys been in business for awhile?" asked a CALL7 Investigator on hidden camera.

"About three years," said Cary Grant, the owner of 3C's RV Rental.

"The deposit? How does that work?" asked the CALL7 Investigator.

"It's $850 and we take it on your credit card and it's paid back 25 days after you return the RV with no damages," said Grant.

"So it's actually a hold on my credit card or it actually passes?" asked the investigator.

"It runs it," said Grant, who recently changed the name of her company to RV Rentals of DIA, following some bad publicity on the internet. The new company is soliciting customers.

"I started calling 30 business days after [returning the RV] and never got any answer back from them. Never heard anything back," Bill Craig told CALL7 Investigator John Ferrugia.

Craig rented an RV from Grant in 2010.

"Never got your check?" asked Ferrugia.

"Never got my check," said Craig.

He was not alone. 7NEWS has obtained a list of nearly two dozen customers from around the country who shared similar stories with Ferrugia.

"They kept the $850 and use it in a different part of the business," said Jeremy Gurley. He worked for 3C's RV until recently. Gurley now has his own business repairing RVs and trailers.

"If I was renting an RV, what happened to my $850?" asked Ferrugia.

"It was spent. Spent in different parts of the business, for parts, or to pay back somebody else's deposit," said Gurley.

"Basically a shell game?" asked Ferrugia.

"Sure," said Gurley.

Ferrugia has also confirmed that many of the RVs rented by Grant were actually owned by others who were trying to make some rental money while they were not using the RV's.

According to Gurley and RV owner David Kerschen, the RVs were insured by Grant but when they were damaged she would not repair them.

"She told [Kerschen] she had filed a claim and it was denied by the insurance company," said Gurley.

"And did she ever file a claim?" asked Ferrugia.

"No, she didn't," claimed Gurley.

Kerschen verified Gurley's claims with 7NEWS and contacted the insurance company himself. He was able to get a check for the damage.

"She didn't want to file a claim for fear the insurance company would drop her for next year's rentals," said Gurley.

With a camera rolling, Ferrugia asked Grant, "I am wondering if you're telling customers that you haven't given people back their deposits?"

"That's actually not true," said Grant.

"Are you scamming people?" asked Ferrugia.

"Absolutely not," exclaimed Grant.

She then asked Ferrugia and the photojournalist to leave the property, but later agreed to sit down for an on-camera interview. She never showed.

Days later, in an e-mail to 7NEWS, she said her company had fallen on tough financial times and that all her customers would receive their deposits back.

But, several of her previous customers have called us to say that Grant has recently tried to place other charges on their credit cards.

Grant has claimed that the companies that process credit cards are withholding thousands of dollars from her, but the CALL7 Investigators have confirmed that Grant's company owes tens of thousands of dollars to those companies, in part, because Grant's customers are disputing the "deposit" charges.

"Do you think she scammed you?" Ferrugia asked Craig.

"Oh, most definitely. Most definitely, yeah," replied Craig.

The CALL7 Investigators have also confirmed that there are complaints against 3C's RV on file at the Colorado Attorney General's Office of Consumer Protection. If you have a complaint against any business, you can call 800-222-4444 or file a complaint online at www.coloradoattorneygeneral.gov -- click on "File Consumer Complaint"