Commonwealth Bank’s online systems suffered another meltdown on Friday morning that left thousands of customers across the country marooned as they tried to pay for petrol, groceries and public transport fares.

The latest failure of the bank’s volatile systems followed a shocking week for customers, that was marked by intermittent disruptions to online banking services, the eftpos system and automatic tellers.

CBA’s systems have suffered four major outages since August 28 when credit card accounts were duplicating accounting entries on customer transactions.

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In a statement on Facebook, CBA said they were working to resolve the issue.

“We’re currently experiencing intermittent issues accessing some of our systems,” the post read.

“The cause is under urgent investigation and we’re working to have full services restored as a priority. We apologise for the inconvenience and thank you for your patience.”

In recent years, the bank had spent hundreds of millions of dollars trying to integrate its systems so that customers were able to see all their account details for deposits, home loans and financial products from a single portal.

As part of the project the bank performed a major “upgrade” of the Netbank technology platform on August 8

However, the integration program appeared to have destabilised the bank’s systems.

Meanwhile, on Thursday, many of the bank’s online share trading customers were shut out of the service because of the ongoing problems with the internet banking systems.

CBA’s banking systems also froze on September 6.

Customers received this message on CommBank’s internet banking. Photo: CommBank

Angry customers took their concerns straight to the source.

“You offline AGAIN! This is happening far too often. Should we start moving our accounts to another bank so we can have guaranteed access to our money,” Amanda Kuhn wrote on Facebook.

“I understand your (sic) doing your best but some of us have multiple business merchant terminals with you. If you would be able to just keep us in the loop so we know when we can tell customers we have eftpos facilities again that would be amazing,” Emily Belle posted.

We’re currently experiencing issues with some of our systems & we are investigating as a priority. Thank you for your patience.

— CommBank (@CommBank) September 10, 2015

More to come.