Do your homework
Once you've calmed down, take time to do some research about your problem, Marco says. She says it's important to know your rights before you call customer service.
Make sure you have the facts straight about your problem, including dates, your account number and erroneous costs. Take a look around the Internet, especially the CFPB's website, to see if other people are having the same problems as you, and how they were resolved, Banks says.
Sometimes, a perceived error may simply be miscommunication on the part of the bank, says Sahm with Carlisle & Gallagher. For instance, she says a consumer may not realize there was a fee tied to a new checking account and may think the charge is erroneous.
Or similarly, she says there are limitations to what a bank can do to modify a mortgage in this regulatory environment. So a bank may not be able to do what a customer wants, and the customer leaves feeling like the problem hasn't been resolved.
"A bank may say, 'We've created a solution.' But a customer walks away saying, 'That's no solution,'" Sahm says. She suggests consumers come prepared to propose a solution.