A year ago, four people were injured in a stabbing inside a Dunedin supermarket.
Two of the four people injured were Countdown staff members, who're both still suffering from their injuries.
Last week Luke James Lambert was jailed for 13 years, having previously admitted four counts of attempted murder.
Countdown says after any serious incident, it always reviews its systems and processes, and even though the attack in Dunedin was completely unprovoked, it did make some changes.
But First Union says it's not enough.
"We haven't seen as much change as we'd like, we think a lot more needs to be done" says First Union's national retail organiser Ben Peterson.
"There needs to be a much more universal security coverage in retail stores, there needs to be more staffing in stores and less teams working isolated or with few people around and we need to see that happen now, that hasn't really happened there's an ongoing pressure to keep staffing down and that leaves people really exposed."
The union says it's seeing a concerning increase in customer aggression, and more preventative measures need to be taken.
"When we see incidents like this, supermarkets or an employer will put on security in the response to but we need to move away from just being responsive to incidents and move to a one where we're being more proactive, it's not really good enough to make supermarkets safer after an incident, we need to make it a safe place to work every day."
Countdown's Kiri Hannifin says the unpredictability of customer behaviour is the biggest concern.
"We've got three million people coming through our stores each week so it's a lot of people, they're very open settings as you know, the doors are kind of wide open and so it's very difficult to control who comes in and Dunedin was an example where we just couldn't have predicted that," she said.
While Countdown acknowledges responsibility over the issue, it says it can't fix it alone.
"I think as a whole society we can and we probably need to do a lot more because there's a lot of retail workers in New Zealand and bank workers and A&E nurses, there's a lot of people on the front line, cops themselves who are getting really poorly treated and it's not ok," Hannifin said.
Peterson says it's campaigning to ensure an attack like this doesn't happen again "so that means having adequate security, having adequate staff and it means changing social attitudes that mean that people see retail as a place to take out their frustration is acceptable we need to change that".
"I think we need to have a whole of society approach to this we can't just put it onto putting security guards on doors is going to solve the issue the way we relate to retail and respect retail is really important part of that is if we leave it as a minimum wage industry where people go as a last resort, then that's going to be the place people don't respect so we need to change attitudes in a range of ways," Peterson said.
In November, the police set up a retail crime unit, focused on helping retailers keep staff safe.
Police Minister Poto Williams says it was established in response to the Dunedin attack, as well as further issues raised by other retailers.
It's already proving beneficial, according to Countdown.
"It's very responsive, so I've got direct contact with the police officers running it so that feels good that there's someone to talk to and test ideas with," Hannifin said.
"They're happy to review stuff and work with the whole sector for a collective response which I think is really important because we're all facing the same issues and we're probably all going to have the same solutions so that sort of coordination but just I think availability and dedication feels really really good and they've made some great grounds."
The unit has already helped to catch some of Countdown's most prolific shoplifters.
"For them to carve off a special unit looking after us, it does really feel like an acknowledgement of the difficulties and challenges that we've had and continue to have so I'm really very grateful to the police."