An Australian mother who reported her 14-year-old’s Snapchat account has been rebuffed by the social media company, because his self-declared age was 25.

Parents of teens who have eluded the social media ban have been told to report their children’s accounts to the platforms to get them kicked off, but some platforms are not acting on it, Guardian Australia can reveal.

Amanda*, a Tasmanian mother, reported her son’s account to Snapchat this month as being an account held by a teen under 16 in Australia.

In communications seen by Guardian Australia, Snap acknowledged Amanda’s complaint, but said it ultimately took no action on the account.

“As a parent I feel angry, dismayed and honestly quite vulnerable about how this process has unfolded,” Amanda said. “I reported an account belonging to my 14-year-old through the proper channels and expected that a clear underage report from a parent would be enough for the platform to act.”

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The teen’s self-declared age in the app is 25, and there were no signals in the account’s behaviour to indicate it was held by someone under 16, so the account was not locked, Snap said.

“We investigated this report but given the declared age of the user is over 16 and all inferred age signals pointed to an age over 16, we could not verify that this user is under 16,” a Snap spokesperson told Guardian Australia.

Given Snap does not examine the contents of messages, there are limited signals in account behaviour to suggest someone might be underage. If the company were to lock any account after a report suggesting that user might be underage, it could lead to malicious false reports of users 16 years and over, Snap said.

A spokesperson for eSafety on Tuesday said it had heard from other parents in similar situations to Amanda, who weren’t able to get their teens’ accounts removed.

“eSafety has received similar reports and is actively engaging with industry – including Snap – about our expectations for compliance,” a spokesperson said.

“eSafety’s regulatory guidance makes clear that eSafety considers reasonable steps include providing accessible pathways for people to report potential underage account holders to trigger further age assurance processes and taking a layered or ‘waterfall’ approach across the user journey.”

The spokesperson said a platform – when a report is not suspected to be malicious – should require that user to go through some form of age verification rather than relying on previous age inference signals such as self-declared age or facial age estimation.

“eSafety is concerned that some platforms are not doing enough and we are progressing regulatory investigations,” they said.

In January, when the federal government was keen to trumpet the success of the social media ban in the removal of nearly 5m Australian accounts from 10 social media platforms, the eSafety commissioner, Julie Inman Grant, told parents they could report their teens’ accounts to the platforms directly.

“If they want the platforms to know … we’ve asked them specifically to have information flows for that,” she said. “This allows them to know where they failed and then to improve their classifiers.”

A News Corp survey this week of nearly 300 teens between the ages of 10 and 16 found 70% of them had not been booted off social media when the ban came into effect in December.

The Snap spokesperson said Snapchat had warned about technical challenges in preventing young people from using the apps when the ban was brought in.

“This is one such challenge. We continue to believe there are better solutions to age verification that can be implemented at the primary points of entry, such as the operating system (OS), device, or app store levels,” the spokesperson said.

“In the meantime, we continue to assess every report we receive of users believed to be under 16 and disable or lock all accounts found to be non-compliant.”

After Guardian Australia’s enquiries, the company contacted Amanda to provide ID documentation for her son, and his account was shut down on Wednesday.

Amanda said while the government had promised the ban would make it easier for parents, “the reality of trying to enforce them has left me feeling that the burden has been pushed back on to families”.

“If governments are serious about minimum age rules, should platforms be required to implement technology such as facial age estimation or ongoing age verification rather than relying on parents to report accounts and provide ID?”

The eSafety commissioner last month announced a study following more than 4,000 teens and parents to measure the success of the ban over the coming years.

* Names have been changed