'Complimentary bags are meant to be an interim measure to help customers make the transition to reusable bags, ' a spokesperson for Coles said.
The supermarket's chief executive office John Durkan sent an email to his 115,000 staff.
Australia is among places grappling with bans, but it has struck teething pains amid what many have likened to "tantrums" by change-averse customers.
Despite Coles customers being notified on their receipts and also on checkout screens that free bags were coming to an end on August 1 a Coles spokeswoman confirmed otherwise.
Coles announced it will scrap the 15c charge for the thicker, reusable plastic bags it rolled out across stores when the plastic bag ban came into effect on July 1.
"Giving away reusable plastic bags is an environmental disaster, this just increases the amount of plastic that will now make its way into our waterways", he said in a statement on Wednesday.
But Environmental groups have reacted with horror.
With a PR disaster looming and calls for a boycott mounting, Coles on Thursday backflipped again, saying the 15 cent bags would only be free until August 29.
Over 3000 people have signed the petition as of this morning.
Harris Farm Markets has historically been vocal about the issue, previously teaming up with Clean Up Australia, who this afternoon also displayed displeasure at Coles' announcement.
Coles implemented the ban on single-use plastic bags in stores across New South Wales, Melbourne, Queensland and Western Australia on July 1, prompting mass outrage over the inconvenience.
"We've been delighted to see customers grow more accustomed to bringing their reusable bags from home so they are relying less on complimentary bags at the checkout".
In July 2017, both Coles and Woolworths announced they would phase out single-use plastic bags.
However customer on social media were not placated.
The decision sparked claims the company was "making a mockery of their stated commitment to reduce plastic waste".
Greenpeace have criticised the decision as irresponsible and disappointing, saying that Coles is perpetuating the problem of plastic waste by providing free bags.
"And please don't get me started on the wasteful plastic mini-Coles supermarket toys, while they promote their anti-plastic message".
"We now renew our call to Gladys Berejiklian and the State Government to enforce a ban of single use plastic bags immediately", he said.