He was seen with it in footage from a surveillance camera the night of the attempted robbery.
He was wearing a "witch-type mask" to conceal his identity when he went into the store on November 11 just before closing time.
He had been outside observing customers while receiving and sending text messages to an associate, discussing how many people were present as the business was about to close.
Entering the store and brandishing the shotgun, he demanded the worker give him cash as he aimed the shotgun within a few centimetres of her chest and moved closer.
She continually refused and he soon left the petrol station without any money or physically injuring the victim.
The court was told she had been left traumatised by the event.
Rongonui's crime spree began on October 18 with burglaries in Levin, Wairarapa and Hawke's Bay where he stole property including a .22 rifle, chainsaws, jewellery, video game consoles, iPods and computers.
On November 22 Rongonui was in the Whakatu area, entered a number of properties before stealing a car and driving to Waipawa and breaking into another home where he stole the .22 rifle and chainsaw.
He then went to Dannevirke Golf Club and broke into a farm shed, stealing two more chainsaws but he was confronted by a staff member who leaned into the car and took the car keys, prompting Rongonui to take off across a paddock.
After running a short distance he found a car parked on Tamaki River Rd with the keys in the ignition and stealing it, headed south where he broke into another property in Fielding.
Throughout this crime spree, Rongonui was in constant text contact with an associate providing him with a blow-by-blow account of what he had done and what he intended to do with the property, the summary states.
He was eventually caught by police on December 12.
Judge Adeane remanded Rongonui in custody for sentencing next month.
