The South Australia government agency fined six petrol stations nearly $20,000 for illegal pricing.
The monitoring team ran checks and found faults mainly around pricing rules.
Customers were urged to call in if they spotted excessive fees at pumps during the inspection.
No company identifiers or location details were released yet.
Total fines total after latest patrol visits.
In Greater Western Sydney, Blacktown motorists now spend extra for fuel than adjacent areas.
Regular pump checks show the area’s prices exceed other nearby spots.
The gap means drivers there face higher costs per litre each time they fill up.
The gap has grown bigger than what regulators expect in typical regional swings.