St George Bank, Bank of Melbourne and BankSA have suffered an outage following scheduled maintenance. Credit:Virginia Star "IBM IMS and CSC Hogan experts are trying to figure out how to restore the databases without losing any transactions that were done on Sunday morning," the source said on Monday afternoon, referring to IT outsourcers IBM and CSC being called in to assist, and Hogan, an integrated suite of core banking applications. "That's clearly not an easy task and is taking a lot of time," the source said, adding: "Customers deserve to know what's happening." A second source close to the outage said it was "very, very rare" for any bank's core system to go down. They added that if Westpac could not recover the transactional files of its smaller banks, it faced the very real risk of losing potentially millions of dollars. As the outage entered more than 28 hours on Monday afternoon, tens of thousands of customers from St George Bank, the Bank of Melbourne and BankSA were left to express their frustration on the banks' Facebook pages.

"Went out for lunch and couldn't transfer money to pay was extremely embarrassing!" St George customer Jules Lewis wrote on the bank's Facebook page on Sunday afternoon. "All plans now cancelled for this evening as we have no access to funds without internet or phone banking....cheers St George." Another customer, Chris Garrett, wrote: "Thanks St George, for the ruined long weekend. Thank you for confining my family to the house as our holiday plans require us to access our money ... This is an absolute joke. "You will be losing a record amount of customers come Tuesday." Another, Brianne Lowe, wrote: "This is absolutely ridiculous!! It's a public holiday and we can't go anywhere or do anything! I can't put petrol in my car, can't buy nappies and I cannot do my food shopping so I have no idea what we will be eating for dinner.

"Hurry up and get it fixed. Your IT guys need a kick up the ass." To add further salt to customers' wounds, the banks' branches were closed on Monday in NSW, Queensland, South Australia and the ACT due to the Labour Day public holiday. In a statement to Fairfax Media, Westpac declined to comment on the reason behind the outage and said closed branches would not be opening. One of the affected banks, St George, added on social media that customers affected would be reimbursed any fees or charges incurred as a result of the outage, which affected online, mobile, and telephone banking. St George Bank first notified customers of the outage via Facebook at 5.13pm AEDT on Sunday, although many customers said they were unable to access their funds before then.