Western Sydney Jump has been widely condemned and a senior Jewish leader has called for mandatory anti-Semitic education nationally after the firm's owner purportedly boasted about refusing a booking from a Sydney Jewish school.
But, in a case of mistaken identity, news of the posts prompted insults and threats towards Western Sydney Jumping Castles and Face Painting.
The owner said she had been told she was a "racist pig", "how about I come and jump up and down on your Nazi face" and a "gutless scumbag" after the phone began ringing from about 4.20am.
"They ring on private and then say s***, so I just don't answer phone calls," Rebecca, who did not want to give her last name, told AAP.
The seven-year-old business's hard-fought five-star Google rating also nosedived.
"I understand people are angry ... but maybe people need to look at the name and logo," Rebecca said.
Executive Council of Australian Jewry co-chief executive Alex Ryvchin said he stood with the innocent business that had "played no part in this, of course".
The abuse was a sign however of the strong feeling in the wider community caused by the exclusionary action of the rival company, he said.
Tensions have risen since Hamas massacred 1200 Israelis and took hostages on October 7, sparking a devastating war in Gaza that has killed at least 11,000 residents, according to Palestinian officials.
"We call all Australians to stand with us to stand united against racism, bigotry and this vile anti-Semitism which is spreading through our society," Mr Ryvchin told reporters.
Alex Ryvchin says a national education program is needed on anti-Semitism.
Premier Chris Minns was also among those to condemn Western Sydney Jump which reportedly rejected a booking request from Masada College because it was a "Zionist booking".
"It's not in keeping with any part of our multicultural community," he said.
"I condemn it completely. This must be investigated by federal and state authorities."
NSW Police were at the school on Wednesday morning making inquiries but had not opened a formal investigation.
Western Sydney Jump's Instagram page, where the post was allegedly made, and its website were offline on Wednesday morning.
Repeated attempts to contact the business owner were unsuccessful.
According to screenshots published by various media outlets, the business's owner tried to draw a distinction between Jews and Zionists in its posts.
The school had attempted to hire novelty-sized games for a party on its St Ives campus.
Even if the discrimination did not constitute a criminal offence, Mr Ryvchin said it was a crime against Australian standards and multiculturalism.
He said a national education program was needed on anti-Semitism, which he dubbed the "oldest hatred" and bloodiest form of racism.
"We also believe in more engagement between Jewish and non-Jewish students to get them together to pierce the stereotypes and mythology that fuels this hatred."
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