A member of staff was injured during the incident.
The victim, who’s in his thirties, was working at the service station on Thame Road at around 1am on 1st August when he was assaulted.
Following an altercation a man slammed the hatch drawer of the night draw window onto the victims hand which caused a deep cut. Officers treated the injury at the scene.
The offender is described as a white man with an average build and around 5ft 9ins tall. He had short hair, was clean shaven and was wearing a white t-shirt. He was driving a silver five door Seat Leon.
Investigating officer PC Daniel Mitchell, based at Abingdon police station said: “There may have been others near the garage at this time who could have witnessed this incident, or drivers in the area who may have dash-cam footage of the vehicle described.
“If you did witness anything, or have any information that might help our investigation, please get in touch.
“You can make a report online or by calling 101 and quoting reference 43200236524.
“Alternatively, if you wish to remain 100% anonymous you can call Crimestoppers on 0800 555 111.”