BEIJING — Two of the world’s leading ballroom-dance instructors were ordered yesterday to repay their most prized client, a Hong Kong investment banker, the $7.5 million-plus that she had paid them to train her in the art of the salsa.

At the end of a case that has both fascinated the territory and provided it with an embarrassing reminder of how its super-rich indulge their whims, 61-year-old Monica Wong won back the deposit that she had given Gaynor Fairweather, the British former world Latin-dance champion, and her husband, Mirko Saccani.

She had sacked the pair after a disagreement during a lesson held in a restaurant when she claimed Mr. Saccani became abusive, calling her a “lazy cow” and telling her to “move your arse.”

When she went to court, they countersued for the remainder of the fees that she had originally promised them, 120 million Hong Kong dollars or $15 million.

But Deputy High Court Judge Gerard Muttrie told them: “I do not see why, even if she was in default, she should not have her money back.”

A string of witnesses from the glitzy world of dance and the even glitzier world of Hong Kong society had given a fascinating glimpse into the passions and neuroses of the city’s normally untouchable millionaire business class.

The colonial craze for tea dances has become in less sedate times a wild, competitive round of salsa and tango, foxtrot and jive, in which “taitais” — a class of housewives often regarded as having little to do other than spend their husbands’ money — compete for attention at charity balls with successful working women, who sacrifice their lunch-hours, evenings, and weekends in an effort to keep up.

Ms. Wong, who is the widowed daughter of a shipping billionaire and wealthy in her own right as head of private investment banking for HSBC in Asia, had become gradually more obsessed with what had begun as a hobby.

She had wanted a “last bit of glory in my life,” she said, when she first hired Mrs. Fairweather, who had won 16 world Latin dance titles and been awarded the MBE before moving to Hong Kong to set up as an instructor.

At the time, Mrs. Fairweather was working with her old partner, Donnie Burns, also MBE, but things changed when the couple split up and Mrs. Fairweather began to work with, and finally married, Mr. Saccani.

At first, the arrangement worked well. Dancing with Mr. Saccani, Ms. Wong took part in competitions, winning the title “Top Gold Lady” at the Los Angeles Emerald Ball in 2003.

But Ms. Wong also feared the couple were losing interest in her and was eventually persuaded to enter into the $15-million, eight-year contract, with just over half as a downpayment.

The fee was so high because she did not want them teaching anyone else, a devotion that appeared reciprocal.

Mrs. Fairweather, 49, told the court that she had come to regard the relationship between her, her husband, and Ms. Wong as “an affair.”

“To me, she’s everything.To me, she’s very special. I love Monica,” she said. “She was my little project, my love, my heart.”

It was not long afterward, in August 2004, that the explosive incident that ended their relationship took place, at a packed venue where 50 people were also practicing, including Mr. Burns and one of his students.

Mr. Saccani was not happy with Ms. Wong’s performance.

But he said that calling her dancing “f—-ing horrible” and telling her to “move her arse” had been motivational language only.

He denied her claim that he had threatened to smash her head against a wall and throw her out of the window. “I’m not aggressive. I’m not abusive,” he said.”I didn’t see her as my student. We were partners.” Ms. Wong said she had been unable to continue lessons after suffering an “emotional breakdown” because of his insults and the public humiliation. Neither side commented after the written verdict Tuesday. Ms. Fairweather and Mr. Saccani’s telephone was not working last night. They are said to have already spent a large part of Ms. Wong’s down-payment — he on a Ferrari and she on cosmetic surgery.