"I was the only customer in the store," Albert wrote. "I knew it was directed at me. I was mortified. I quickly bought the two things I had in my hand that I had found and left the store. I was so embarrassed! I had a work function to go to that night, when I got back to my hotel I cried in the shower."
he said that while "not everyone fits into Lulu", at a US size 10/12 (Australian size 14 to 16) I'm not even close to maxing out on size there!"
In a testament to the brand's allure, rather than threatening to boycott Lululemon, Albert said she would "stick to the outlets and online shopping from now on".
A Lululemon representative apologised to Albert for her experience and promised to "dig into this further and help to make things right".
The incident comes as the global activewear company, which has 25 stores in Australia, ploughs millions of dollars into its local operation in a bid to steal market share from competitors like Lorna Jane, which has 200 stores - and is also known for its controversial stance on body size.
The company's latest financial accounts show that it invested $19.73 million into its Australian business in the 2016 financial year, Fairfax Media reports.
The strategy, which includes a national marketing blitz, appears to have worked. Lululemon Australia transformed its financial performance in 2016, turning a $6.8 million profit - in contrast to the previous year's $7.2 million loss.
Annual sales grew by 16 per cent to $98 million in what is the company's third biggest market outside of the United States and its native Canada.