Angry customers are costing call center workers more than their patience.

New research conducted by a group of professors in the US and China reveals that customer service reps who suffer “verbal abuse” from people over the phone are more likely to try making themselves feel better by binge shopping later, according to Michigan State University.

The study, published in the Academy of Management Journal, monitored 94 call center employees in China for 15 days. Researchers studied their reactions to being lambasted by irritated customers over the phone, and found that employees who had been harangued, shouted at, or cursed at were prone to perk themselves up with a round of retail therapy after work.

“Such shopping [can cause] serious financial problems…threatening individuals’ mental health in the long run,” the authors of the report wrote. “We found that call center employees tended to buy things beyond their spending power after being mistreated by customers,” Russell Johnson, a professor at MSU and co-author of the study, told Moneyish.

Of course, most of us don’t want to do any such thing to a customer service worker; instead we just want to get our issue resolved. So how do you keep from getting frustrated at customer service on the phone — and still get what you want from them? Moneyish asked the experts.

First, even when you’re angry, try to stay measured and polite. A great strategy is to consider how the other person feels, according to the authors of the report, who wrote: “One of the main ways to be socially mindful of others is to try and take their perspective.”

Having a calm and kind attitude with customer service reps can increase your chances of getting assistance, receiving a discount, or scoring a deal.

Once you’re calmly engaging with the rep, take the advice that former FBI negotiator Chris Voss shared with Moneyish about how to get what you want.

Watch this: An FBI hostage negotiator shows you how to win with a customer service rep

1. Empathize with them. Break the ice with a congenial conversation-starter, like: “I’m sure you’ve had your fill of dealing with demanding, self-absorbed, whining customers all day long,” Voss recommends.

2. Point out the problem. For example: If you’re calling your cable company to get the rate they offer new customers, Voss suggests identifying the dilemma politely. Try something like this: “It seems like you value new customers more than you value loyal, long-term customers.” Then go silent, and wait for the response on the other end.

3. Float like a butterfly, sting like a bee. Voss says that if all else fails, wrap up the discussion with a line like this: “Wow, you’ve been really generous with your time; sounds like you’re powerless.” He says this will likely spur the customer rep to call a supervisor and work extra hard to deliver a result.