Eftpos Payments Australia was aware that at least two large banks would pass on the increased cost of changes to Eftpos interchange fees to their merchant customers when it issued a press release in August saying consumers "should not face" new charges as a result of the changes.This claim is at the heart of a case of misleading and deceptive conduct brought against EPAL by the retailer, Aldi Stores, which will be heard in the Federal Court next week.Counsel for Aldi claimed in a directions hearing yesterday that Westpac and National Australia Bank had notified their merchant customers that changes to Eftpos fees would result in higher charges - 10 cents per transaction in Westpac's case.Aldi's contention is that the banks were telling retailers about their plans, which could result in significant charges being passed on from retailers to consumers, at the same time that EPAL issued its press release.Aldi's case is that EPAL must have known about the bank's plans, given that Westpac and NAB are part-owners of EPAL.Aldi also argues that a clarification issued by EPAL, on September 8, saying that "it remains to be seen… what retailers may do in relation to their customers", was also misleading.The background to the case goes back to March, when EPAL announced it would change its interchange fee model. Interchange fees are wholesale payments made between the consumer's bank and the merchant's bank, for handling Eftpos transactions.In broad terms, under the old model, fees were paid by the consumer's bank (the issuing bank) to the merchant's bank (the acquiring bank). Under the new model, the direction of payments will be reversed.Retailers like Aldi are concerned that they will face higher costs for Eftpos transactions, as acquirers recover their costs, and this will put pressure on their margins.Not all retailers will be in this position. Coles and Woolworths do their own acquiring (transaction processing) and will not face any new charges.The EPAL case, outlined at yesterday's hearing, is that Aldi is worried about being put at a disadvantage compared with its big supermarket rivals and is trying to put pressure on EPAL to come up with a more favourable deal.According to EPAL's counsel, Aldi's managing director had a meeting with the managing director of EPAL two days after Aldi made its complaint about misleading and deceptive conduct, and offered to drop the action if terms could be reached.EPAL will argue, in defence of the claim of misleading and deceptive conduct, that there is nothing deceptive about saying that "it remains to be seen whether acquirers will pass part or all of any fee changes on to retailers, and what retailers may do in relation to their consumers."Its position is that different retailers, given their size and other circumstances, will negotiate different deals with their acquiring banks and make different decisions about customer charges.