Commonwealth Bank of Australia is playing hard ball against victims of failed managed investment scheme Willmott Forests, levying penalty interest rates over the period of a long-running class action against the bank, which has doubled the amount owed by some investors. The Federal Court of Australia will decide on July 23 whether to approve the settlement of a class action brought by 3500 investors against Willmott Forests, which is in liquidation, and CBA, which is understood to have lent more than $200 million to investors in the scheme.