Last night (January 29), at around 10pm, a man entered the store in Mill Road, threatened staff and forced the till open.
He took money before fleeing the scene towards Braeburn Way.
The offender was described as a white man, of slim build, wearing black clothing and a black mask.
Detective sergeant Simon Hancock said: “I would like to appeal to anyone who was in the area at the time and witnessed anything suspicious to come forward.
“We would also like anyone in the area who has CCTV or dashcam footage to come forward.”
Anyone with information about this incident is asked to contact police on 101 or using the force’s online reporting centre, quoting the reference number 40/5992/20.
Alternatively you can contact Crimestoppers anonymously on 0800 555 111.