A former investment promoter today backed out of an agreement to plead guilty to charges that he swindled customers. Prosecutors say George Fiorini was expected to plead guilty to mail fraud and tax evasion. The suburban Cincinnati businessman was accused of promising customers through television advertisements that he would pay them ten percent interest on investments. But his customers say he cheated them out of the money they trusted him to invest for them. Fiorini appeared in federal court today and maintains he is innocent of the charges. His trial is set to start November 18th. A former Fiorini associate, Stephen Ventre, pleaded guilty in May to a federal charge of mail fraud in connection with the investigation.