They say they never received promised products and services.
One franchisee who invested $200,000 in the Forte School of Music franchise later sold his business for $1.
Documents obtained by The Courier-Mail show the Australian Competition and Consumer Commission has been investigating Forte since last year but has yet to take action.
Complaints were still being assessed.
Former and current franchisees said Forte earned significant fees for support and products which never arrived or arrived late.
The company provided figures showing franchisees would earn $100,000 or more.
But one franchisee said she worked six days a week and averaged only $50,000.
Forte director Gillian Erskine denied any wrongdoing and told the ACCC she would co-operate with the investigation. She said she was "committed to ensuring every effort is made to satisfy individual franchisee`s reasonable requests".
Darren and Jo Huth, who operated a Forte music school in the Brisbane suburb of Coorparoo, estimated they lost $70,000 in 18 months.
"The time we were running our school as a Forte franchise is a time we would rather forget," he said.
A NSW woman who bought a Forte franchise in 2004 sold her school for a "large loss" in 2007 "due to no longer being able to survive financially".
Forte promoted the franchise as a strong business opportunity that would reap "in the vicinity of $100K profit" a year with 200 students enrolled.
The woman said she paid $8000 for training but it fell far short of expectations.
"We were not given any advice on how to structure our staff and were given only cursory information on bookkeeping and GST," she said.
Another Sydney franchisee said Forte was slow to provide and upgrade materials for music students.
Mr Huth has alleged multiple breaches of the Franchising Code of Conduct. Franchisees say they were bullied and instructed not to communicate with each other. However, after franchisees compared notes "we found we were all in the same situation," the NSW franchisee said.
Repeated calls to Forte`s national office at Toowong went unanswered and Ms Erskine`s partner, Paul Myatt, could not be reached for comment at his Sydney music school.
The Commonwealth Government is reviewing legislation aimed at protecting consumers from unfair franchise contracts.
THE benchmark S&P/ASX200 index was 121.3 points, or 3.1 per cent lower at 3796.9, while the broader All Ordinaries fell 117.8 points, or 3.01 per cent, to 3793
AUSTRALIAN companies are still positive despite having to lay off staff and freeze wages
MORE than 200 CEOs braved a steady downpour last night to take part in St Vincent De Paul Society`s annual CEO sleepout
