A video shows a Starbucks manager screaming at a customer about a cookie straw and ordering her to leave the store.
"Now give me the straw, and leave," the manager of the Queens, New York store is heard shouting. "You're not gonna be served here. Bye."
The manager then demands that someone call the police and threatens Chen with arrest.
Chen said she ordered a Frappuccino and was trying to open her Starbucks Rewards app on her phone when the manager started yelling at her.
"She took the scanner away as I was trying to pay then told me to leave and never go back," Chen said in a post on Facebook.
Starbucks says the employee has since been fired.
"We take this issue seriously; this experience does not represent the high service standards we set for ourselves," the company said on its Facebook page. "This partner no longer works for Starbucks."