Someone (married) close to our family had almost the exact same issue described in the OP, with the additional point that the worker “mistakenly” brushed against her. She asked a shaila from her Rov (who is one of the gedolei poskim in ny) and he told her:
a) Call the store’s mashgiach AND the store’s owner and tell them what happened.
b) Do NOT shop there anymore until that person is fired.
(A Rov MUST be consulted prior to whatever you do.)