The case follows the battle between Mattel and MGA regarding the copyright of the dolls.
Supply of the line has been suspended following US litigation, Funtastic said in its annual report filed last week.
"Funtastic has been unable to secure supply of new ranges," chairman Graeme Yeomans told the exchange in the report.
In a statement lodged with the Federal Court, Funtastic alleged it had suffered damage after MGA Entertainment said it would no longer supply Bratz after the end of 2009.
Funtastic alleges it was misled by a promise made by the firm's Hong Kong subsidiary that the dolls did not "constitute an infringement of any intellectual property right vested in any third party."
Although MGA has yet to pay the money awarded by the court to Mattel, and has appealed against the judgment, Funtastic alleges that the order means MGA's promises were "false and/or misleading or deceptive".
In its statement, Funtastic said that in October 2009, it asked MGA to repay an $8.8 million deposit previously handed over for Bratz shipments.
"MGA has failed to repay to Funtastic any part of the purchase deposit," the firm alleged.
Funtastic is seeking repayment of all $20 million in deposits it has paid MGA since signing the Bratz deal in 2004, a declaration MGA has breached the Trade Practices Act, damages, interest and costs.
MGA has yet to file a defence to the claim, and a hearing has been set down for May 18th in Melbourne.