The shopowner said other items stolen included soccer boots, underwear and other items of clothing from other Dunedin retailers.
It appeared teens were stealing to order, following requests on social networking sites from their peers, she said.
The organised nature of the shoplifting has prompted the Otago Chamber of Commerce to organise a special theft prevention workshop for city retailers.
"It is important, because it is a cost on retailers and ultimately a cost on us as consumers, because you end up having to pay for what someone is stealing," chief executive John Christie said.
The use of social networking sites to steal to order was a "disturbing trend".
Some retailers had no idea on how much stock had been stolen, and many were now opting to beef up security.
Retailers interested in attending the theft prevention workshop were urged to contact the Chamber of Commerce.