Optus has been labelled a “clown show” amid mounting rage over its refusal to commit to compensation for customers affected by Wednesday’s national outage.

Optus chief executive Kelly Bayer Rosmarin has so far suggested “rewarding” loyal customers, but has not expressly promised redress, even though some businesses lost an entire day’s trade.

Australian Chamber of Commerce CEO Andrew McKellar on Thursday said Optus’s handling of the unprecedented network crash was a “fiasco” and it was turning into a “clown show” as the telco dodged questions of compensation.

“Certainly some level of recompense is the fair thing or compensation is the fair thing. [It] is the right thing to do and we would urge Optus to do the right thing to those customers,” he said on ABC TV on Thursday.

“We haven’t had any clear indication from Optus about what they are proposing, but certainly there is every argument there that there should be some level of financial recompense to those customers.”

When asked about media reports that Bayer Rosmarin had suggested a refund to customers would amount to just $2 each, McKeller fumed.

“Honestly it’s been a clown show from Optus in terms of their communication; I don’t think that’s anywhere near enough but the ball is in their court,” he said.

“They have to really look hard at the way in which they are serving their customers … otherwise people can vote with their feet.”

McKeller said Optus had about 400,000 businesses on its books.

The Albanese government on Thursday announced a review would be conducted into the outage.

Meanwhile, the Telecommunications Industry Ombudsman urged small businesses to contact Optus to discuss options for compensation.

“What we would encourage you to do is contact Optus and … help them understand what the impact was on them and their earnings,” TIO Cynthia Gebert said.

“That’s the sort of thing that we think you need to tell Optus so they get a sense of what sort of compensation might be the right thing to do for your circumstances.”

Gebert said the scale of the outage was unacceptable as it hit emergency services and hospitals, as well as small businesses and transport services.

Financial Services Minister Stephen Jones slammed Optus’ response as “absolutely subpar”.

“You’d have thought coming off the back of the previous data breach where they were facing similar calls from customers to explain exactly what was going on, this simply wasn’t good enough,” he told ABC’s RN.

Businesses are counting the costs after the nationwide outage ground trading to a halt.

More than 10 million customers and businesses were thrown into disarray from about 4am on Wednesday, with customers unable to connect to the internet or make or receive calls.

People weren’t able to call triple zero on landline devices, although it was still possible to do so on a mobile phone.

It took more than 12 hours to restore services.

Bayer Rosmarin said the cause of the blackout was a “technical explanation”.

“There is no soundbite that is going to do it justice, so we want to really bottom out the root cause and when we have that very clear and in a digestible form, we will be forthcoming,” she told the Australian Financial Review.

Bayer Rosmarin said she had “no idea” how long it would take to do a “full and thorough root cause analysis”.

The outage was not “something unusual in the grand scheme of things when you’re operating a critical infrastructure like we are”, she said.

The Greens are pushing for an inquiry in the Senate.

“Clearly people were pretty frustrated yesterday. Some people were extremely angry that their entire day’s work had been thrown out the window. Banking was effectively crashed for many people. They couldn’t do their business,” Greens senator Sarah Hanson-Young said.

“We should, through this process, find out how much this really cost the Australian economy. I know parents were angry – and frustrated that they couldn’t take their kids to childcare because childcare centres had to close. If you can’t contact the parents, then you can’t really take responsibility for children.

“Schools were impacted. Health services, hospitals, emergency services. It was chaos. Now, we’ve got to look at why this happened, what the potential compensation for those that have been deeply impacted by this could be – and how we fix it.”

National Retail Association director Rob Godwin said businesses had been dealt multiple blows, a day after the Reserve Bank increased interest rates.,

“This is costing businesses thousands of dollars in sales that they are now in dire need of given yesterday’s rate hike,” he said.

Victorian Premier Jacinta Allan said her government would review its contracts with Optus, as well as the telco’s response.”

“Whether you’re a small business operator here in Victoria, someone trying to get to work on the train … it was a really, really disappointing incident,” she said.

Optus is one of 23 telecommunication providers contracted by the Victorian government.

Almost 10 million Optus customers had their personal information stolen during a massive data breach last year.

-with AAP