WASHINGTON – Last June a member of the military who owed money on a car complained to federal regulators about harassing phone calls from a debt collector.

This collector wasn’t just asking for money.

“They began to call and threaten me over the phone to include contacting my commanding officers,” the service member wrote in a complaint to the Consumer Financial Protection Bureau, which does not identify individuals who contact it or their military branch.

Complaints filed by some of the 1.3 million active members of the military over collections calls reflect the difficult situations they can face managing affairs while stationed overseas.

The complaints also show how debt collectors use aggressive — and sometimes illegal —  means to hound vulnerable service members, according to the bureau and veterans groups.

Military members appear to have problems with collections agencies, in particular, the bureau said. Nearly half of 19,000 complaints it received from service members last year dealt with debt collectors – about twice the portion reported by civilians.

Unscrupulous debt collectors exploit ways that service members are vulnerable, according to consumer advocates. For example, poor credit can jeopardize security clearances, said Holly Petraeus, an assistant director for the consumer bureau.

“Many debt collectors are aware of this, and some use that knowledge to threaten service members about losing their security clearance or contacting their chain of command if a debt isn’t paid,” she said in a statement.

The tactics are illegal, the agency said.

Last year the consumer bureau sued an Ohio auto finance company, Security National Automotive Acceptance Company LLC, accusing it of violating the Fair Lending Act for threatening to report service members’ indebtedness up the chain of command.

In some cases, the agency charged, collectors called and wrote superior officers, alleging members of the armed services violated the military code of conduct by falling behind in payments.

The consumer bureau also accused the company of deceptive practices. It told service members they could be demoted, discharged, denied reenlistment, stripped of security clearance or re-assigned if they didn’t pay up.

All “were extremely unlikely to occur,” the lawsuit said.

The company agreed to pay the service members $2.6 million, in addition to a $1 million penalty, and to stop threatening to contact borrowers’ superior officers.

In December 2014, the consumer bureau and attorneys general of North Carolina and Virginia sued Freedom Stores Inc. for lending act violations against service members.

The company and its affiliates – which sell furniture and electronics on credit at stores around military bases – “would contact the officers in writing and by phone to disclose the debts, humiliating the service members and putting their careers at risk,” the lawsuit said.

In a complaint to the consumer bureau last June, one service member said the stores “contacted my command repeatedly – even after I returned the merchandise and secured a letter from a store manager releasing me from any contractual obligations, as I was ordered by my command.”

“It’s the lowest of the low,” Aleks Morosky, deputy director of the Veterans of Foreign Wars, said of the pressure tactics, which are also used against military members serving overseas.

Those out-of-country assignments present their own set of challenges, the consumer bureau said.

Some service members return to the United States to find fraudulent charges that they hadn’t noticed on their credit cards and bank accounts, according to the bureau. Others complain that they were unaware of stipulations in auto loans barring them from taking cars overseas.

Cindy Sebrell, vice president of public affairs for the debt collectors’ industry group ACA International, called threats to contact superior officers or jeopardize security clearances “unacceptable and unlawful.”

“A reputable debt collection agency would not engage in this practice, and ACA does not condone it,” she said.

Still, the association disputed the scale of the problem.

The consumer bureau reports all complaints – including unsubstantiated ones – not the number of cases when debt collectors are found to have acted improperly, she said.

Debt collectors respond quickly to complaints relayed by the consumer bureau 92 percent of the time, Sebrell said, and an “overwhelming majority” are resolved amicably.

The bureau last year signaled that it is reviewing debt collectors’ actions, including toward service members, and may propose new rules.

Studies show that many service members worry about their financial situation. According to a survey last year by Blue Star Families, pay and benefits are the top concerns of military families.

Housing allowances are less than market rates, the group noted, and frequent moves bring unexpected expenses.

Pay for active-duty members hasn’t kept up with increases in the private sector for four years because of mandatory spending limits, Morosky said.

Kery Murakami is the Washington, D.C. reporter for CNHI’s newspapers and websites. Reach him at kmurakami@cnhi.com