NSW toll road users have again been mistakenly charged for trips they did not take as a software update is blamed for the latest bungle.
Refunds are being issued to the majority of customers but the ongoing issues are not acceptable, Metropolitan Roads Minister Natalie Ward said.
"I'm looking for a review into that IT contract, it's not acceptable that customers should be inconvenienced because of a backroom IT update. I know they need to be done but they need to test the systems better," Ms Ward told Sydney radio station 2GB on Monday.
The latest mistake resulted in people who have recently purchased a used car being charged for the previous owner's unpaid trips.
Transport for NSW apologised last month after more than 45,000 e-toll customers were overcharged.
"As if toll roads weren't expensive enough, now you're getting tolled for not even using them," Opposition Leader Chris Minns said.
"When you go through a toll road it comes out of your account in seconds, when it needs to be reimbursed, it takes months," he said.
An inquiry hearing into tolls in NSW was cancelled on Friday as parliament instead met to pass amendments to roads and crimes legislations targeting climate change activists who blocked roads and ports.
