Brandao had been expected to join Bastia for the 2014-15 season but they announced on Friday they had sent the 34-year-old back to Saint-Etienne, claiming the Loire-based outfit had demanded a transfer fee at the last minute.
In a statement on their website, Bastia claimed this was "contrary to what was originally planned".
Saint-Etienne rejected Bastia's accusation, before claiming the Corsicans owe them over €150,000 for a transfer involving Sylvain Marchal from 2012.
"Saint-Etienne noted with amazement the statement released Friday by Bastia," a statement on Saint-Etienne's website read.
"Contrary to the leaders of the Corsican club, ASSE have never asked for transfer fee on Brandao.
"In contrast, Bastia has not complied with the financial commitments made when transferring Sylvain Marchal, in July 2012, by not paying the balance due of €155,680."
That was not the end of the online argument, however, as Bastia responded again.
They claimed the transfer involving Marchal had included a clause where Bastia would pay Saint-Etienne if they managed to stay in Ligue 1 for the 2013-14 season.
While Bastia did achieve that, they argued that with Marchal moving to Metz before that campaign began, the fee did not need to be paid.
Bastia had originally announced on Thursday that they had signed Brandao for a season with the option of an extra year but, after the disagreement on Friday, will not be pursuing the striker anymore.
