A police spokeswoman confirmed no-one had been arrested in relation to the robbery.
Police would not discuss the specifics of cash rewards being offered, but said "the amount would vary depending on each circumstance".
"It will be when information leads to successful prosecution," the spokeswoman said.
Police would not say if rewards had been offered under the campaign, citing "confidentiality and operational reasons".
The most recent police statistics show aggravated robberies in the Southern district have risen by more than 25 per cent in the past year.
Speaking at the campaign's launch, police commissioner Mike Bush said it was hoped the campaign would make a dent in the number of violent robberies driving the black market trade in tobacco and stolen goods.
"NZ Police are deeply concerned about the rise in this violent crime due to its significant impact on small-business owners and their workers and communities," he said at the time.
To be eligible for a reward, you would need to provide your details to Crimestoppers when you called, Bush said.
The campaign is scheduled to finish at the end of this month.