Juana Martinez says one quick trip for coffee cost her $212.
At a California Starbucks drive-thru last week, Martinez claims a cashier stole her credit card number and went on a shopping spree. The next day Martinez confronted her.
"You know what you did right?" Martinez said.
"I'm sorry that I took money from you and your kids," the cashier said.
Police say they are now investigating.
Experts say credit card numbers can be stolen by thieves simply writing them down or using high-tech devices called skimmers. That data can be used to make forged cards.
"It's very, very difficult to prevent someone from having one of these magnetic stripe readers which are very small and very portable," expert Austin Berglas said.
Experts say you can help protect your money by frequently checking your bank statements, don't let anybody see your pin number, and if an ATM or card reader looks tampered with, don't use it.
The coffee company calls the situation "completely unacceptable" and says the employee "no longer works for Starbucks."
VIDEO: Customer confronts Starbucks cashier who allegedly stole credit card number