A Quincy woman faces an assault charge saying she punched a restaurant worker for putting too many pickles on her steak-and\-cheese sandwich, police said Monday. Tina Drouin, 49, ordered the sub from Nathan’s Famous Hot Dogs in the Quincy Center subway and commuter rail station at about 2 p.m. Saturday, said MBTA Transit police. Drouin started loudly complaining, used a profanity, and made other derogatory comments about the ratio of certain ingredients as the worker prepared the sandwich, Transit Police said. Finally, she demanded a refund. The worker refused. Police said that is when Drouin punched the female worker in the face and pushed over two large pickle jars.