Concert producers Groove Dance Productions said they were contacted three hours before the children were due to be on stage and were told Panthers had double booked the auditorium with an NRMA travelling roadshow.

The club organised Newcastle City Hall as an alternative venue but it only angered organisers who said it was an unsafe plan because the children, aged two and above, had no time to rehearse in the new venue and it was too small.

Principal Nerrida Bushell said she booked the auditorium in February and as late as Saturday night was in contact with Panthers completing arrangements, with no word about the change.

She said had spent $15,000 organising the concert and would lose some of that because of the change of venue.

Ms Bushell said some parents and relatives had travelled from interstate for the concert and said Panthers had behaved unprofessionally.

"I've got these kids running into the audience and doing lifts and I tried to explain you can't just change venues it just doesn't work like that," she said. "They're actually ruining my business, not to mention ruining the kids' day."

Panthers general manager Luke Walker said the club would reimburse the booking fee, cover the cost of hiring City Hall and the cost of transport to the hall.

Mr Walker said they also provided staff and refreshments at the City Hall.

He there was an "issue with the room" and there would be a full investigation into the handling of the event.

"We pride ourselves on our high service standards," he said.

"We have gone to every effort to make sure the event was a success."

Belinda McNamee, of East Maitland, said it was "disgraceful" the children had been forced to move to City Hall after rehearsing for almost a year.