A disclosure made yesterday by ASIC executive Michael Saadat has triggered concern among senators over the transparency of recent evidence given by Westpac chief executive, Brian Hartzer to a parliamentary committee.Saadat yesterday confirmed to the senate economics committee that ASIC was told by Westpac in May some of its customers had not received discounts on financial products advertised by the bank.On 19 October Westpac announced in a media release that it would refund A$65 million to 200,000 customers who had missed out on promised discounts for home insurance and deposit products.ACT senator Katy Gallagher told Sadaat and ASIC chairman Greg Medcraft that Hartzer made no reference to the problem when he appeared before the House of Representatives economics committee on 11 October.Instead, the Westpac boss highlighted a string of positive initiatives introduced by the bank including the launch of a low rate credit card and lowering of fees on personal transaction accounts.While Hartzer boasted that it was "putting right" products that were not meeting customer expectations, he elected not to mention that 200,000 customers had been short-changed by the bank. Senator Gallagher said she was surprised that Westpac had skirted the issue during the 11 October hearing given that the regular parliamentary engagements with major bank CEOs were meant to help the industry rebuild trust with the Australian community.ASIC chairman Greg Medcraft agreed that Westpac needed to improve its disclosure practices.A Westpac spokesman defended Mr Hartzer's decision not to disclose details of the service failure at the 11 October hearing, saying that the bank had an obligation to inform the ASX of the big refund program."We needed to inform the ASX and have certainty around the total cost of the refunds," the spokesman said."We're very upfront with all our stakeholders, but we can't be disclosing such important numbers before going to the ASX first."This explanation is not very persuasive.Hartzer could have limited his disclosure to the bank's failure to pass on discounts, without citing how much the remediation program would cost.Moreover, he could have requested the hearing adjourn to an in-camera session before sharing the information with the committee.