 -- A Utah-based home alarm company, once praised by Mitt Romney, is aggressively marketing to military families, and its door-to-door sales force is accused by some of using sales tactics that have earned the company an “F” grade from the Better Business Bureau.

Some salespeople from Vivint Security of Provo, Utah have been accused of misleading the families of U.S. troops and exploiting the concerns of deployed U.S. soldiers for the safety of their families back home.

“Vivint has an F rating with us and the consumers are telling us the sales people are saying one thing, the contract says another,” said Jane Driggs, the executive director of the Better Business Bureau in Utah.

Over the last year, five military families directly contacted The ABC News Fixer, Stephanie Zimmermann, to complain they were stuck with cancellation fees of up to $2,000 when they tried to get out of long term security system contracts after being transferred to a new base or retired due to service-related injuries.

“The sales person on the phone said that it would not be a problem,” said Jason Plummer, a Marine who served in Iraq and Afghanistan and was injured in a roadside bomb attack.

But Plummer said when he got medical retirement orders and prepared to move off base, Vivint refused to let him out of the contract, citing its policy for military customers.

Plummer said he did not realize the language in the contract was at odds with what he was told by the Vivint salespeople.

“It definitely gives you a feeling like you’ve been betrayed,” Plummer said in an interview broadcast today on “Good Morning America”. “It feels like you’re getting stabbed in the back.”

After ABC News contacted Vivint, the company agreed to cancel the Plummers’ contract.

In addition to the Plummers, four other military families also contacted ABC News, claiming Vivint sales people had misled them in the same way over the ability to cancel if they had to move.

Vivint agreed to cancel their contracts too, saying either the families or their company’s own representatives had “misunderstood” the language of the contract.

The Better Business Bureau says Vivint is prepared to deal with individual complaints in order to avoid bad publicity, but has not done enough to correct the “broader” problem of false promises by door-to-door salespeople.

“They need to take care of the underlying issues,” said Driggs of the Better Business Bureau, who says her office has received more than 3000 consumer complaints about Vivint in the past 3 years.

In a written statement, Vivint said it had taken care of the individual complaints from brought to its attention by ABC News and that the overall number of complaints to the BBB represents less than one percent of their large customer base.

The company said it has updated policies for military personnel discharged for medical reasons and “improved our internal communication to our frontline teams.”

Vivint and its sales tactics have been the subject of legal action by the attorneys general of seven states. The company says it has cooperated with all investigations. “We work closely with the agencies to resolve any concerns,” the company said in a statement to ABC News.

When the company opened its new headquarters in 2011, former Presidential candidate Romney helped cut the ceremonial ribbon and commended the company for creating jobs.

A spokesperson for Romney did not return calls seeking comment by the former presidential candidate about the company.

Jason Plummer, the former Marine, says he’s glad to be out from under the crushing payments for an alarm system at a home he had already vacated.

“I mean, when you find out you’re gonna end up paying almost two grand for something you're not gonna use for the next couple years, it's extremely frustrating,” he said.

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