The two phones - an iPhone 6 and 6 plus - were ripped off the display unit. There were four customers and three staff in the store at the time.
"The crazy thing is, all our demo phones are not useable," Mr Nottage said. "They have pre-programmed demo software, which you can't erase."
The man dropped a bracket, which Mr Nottage said police were testing for fingerprints.
The theft caused about $1000 damage to the store's display units.
Mr Nottage said there was little value in stealing phones as New Zealand telecommunication companies had recently agreed to share serial numbers. Phones reported stolen get locked out and blacklisted off the networks.