Infuriated after his credit card was declined, a customer struck a QuickChek employee in the head with a UPC scanner on Saturday morning, Bayonne police said.

The 20-year-old employee refused medical attention at the scene, but told authorities the man became irate and cursed at her when his credit card was declined shortly after 1 a.m. inside the convenience store at 260 Broadway, cops said.

The man left the store, only to return even more upset. He then grabbed the handheld UPC scanner on the counter and threw it at the employee, striking her in the head, cops said.

The incident remains under investigation, police said.