She was disappointed her grandson was left screaming for help outside and no police or members of the public stopped to help him.
She said the incident showed the "problems that have plagued the bus hub since its inception" had not improved since the fatal stabbing in May.
The woman said her 13-year-old grandson was outside the police station about 6pm on Sunday, waiting for his bus, when a trio of teenagers approached him.
"They told him he could give them his shoes, or his cellphone, or we’ll beat you up," the grandmother said.
Her grandson ran up to the central Dunedin police station’s doors, knocked and yelled for help, but nobody came to his aid.
He walked away from the station and the teenage trio said to him "that’s all right, no-one’s in there, we’ll take those shoes now", the grandmother said.
The teenagers took the shoes and her grandson ran down a nearby alleyway and called his mum for help.
His mother raced from Corstorphine and she "almost flew" from her home in Mornington to get to her grandson.
She, the mother and his stepfather all called the police and the call taker informed her "they were getting multiple calls about this incident and they were searching for her grandson".
It was not until she told them "can you actually tell the police to get out of their chairs and actually go outside, because this was happening outside their police station", that police went outside and found the "terrified" 13-year-old.
"My main gripe was that the station was locked — and there was no security guards around at the time either.
"Where do our children go for help? They’ve let him down — he’s terrified."
Her grandson was really rattled and sad that he lost his nearly $300 shoes.
"I said don’t worry about the shoes, we’ll get them back or get you a new pair."
She was also shocked at the actions of the passers-by.
"People were just walking past as he was screaming for help — nobody would help him. I guess people just don’t want to get involved because you just don’t know if they have a weapon," the grandmother said.
Otago Coastal area commander Inspector Marty Gray said he was sorry "to hear that this young person has been the victim of theft in a public place".
"Dunedin police are aware of some ongoing issues with anti-social behaviour at the bus hub and continue to work closely with the Dunedin City Council, Otago Regional Council and other partners to address this issue."
He said extra CCTV was in place and security patrolled the area.
"The front counter of Dunedin central police station is open from 7am to 9pm Monday to Friday and 8.30am to 6pm on weekends and public holidays, and police can be contacted via 111 or 105 outside of those times."
