A teenager had since been arrested and was being dealt with by the Youth Court.
Mr Chen said they were thinking of hiring a security guard.
"It's just left some bad feelings about safety and it makes business even harder."
Police said the latest offender had dark brown skin, an average build and was about 1.8 metres tall.
He was wearing a pair of white cotton gloves, a balaclava, black sport shoes with a white stripe on the side and he was carrying a light grey sweatshirt.
Anyone with information should contact Detective Sergeant Chris Fouhy at the Kaikohe Police Station on (09) 405 2966 or call CrimeStoppers anonymously on 0800 555 111.PNZ