Investigators said the manager was going to refund 38-year-old Tara Lyons' money, but when she turned her back, Lyons hurled the sandwich at her, hitting her back.
The two argued before Lyons tried to climb over the counter.
The manager pushed her back, which caused Lyons to fall and cut her head, but that didn't stop her.
"The customer, still angry of course, gets up and just starts going crazy," said Dani Moschella of the Broward County sheriff's office. "She starts throwing condiments and napkins. There's a coffee pot filled with coffee on the counter. She pushes that over. She tries to go around and get into the manager's door that's locked."
The manager called 911.
Police caught up with Lyons a few feet away from the restaurant as she was walking away.
She faces charges of assault, battery and burglary.