During another visit, members of staff spent three hours persuading her to sign up for a massage, which she refused.
But she said the sales clerk took her credit card and charged her anyway.
She later found out she had been charged a total of HK$110,000 ($20,000) for the two courses of treatment, which she said she could not afford to pay.
The centre, which could not be reached for comment on Tuesday, refused to refund her.
Democratic Party member Yuen Hoi-man, who was assisting the woman, said the case has been reported to Hong Kong Customs and the Consumer Council.
They would report to the police soon and urged the Department of Health to help.
In June, Yuen helped at least 42 victims who said they were duped out a total of HK$2.1 million ($382,236) by men who chatted up women on the internet and took them to beauty salons on a first date.
The women were later asked to pay for the treatment and signed up for courses.
The beauty sector in Hong Kong has long been criticised for unscrupulous selling tactics and the government has been under fire for the slow process in regulating the industry.
- This article first appeared in the South China Morning Post