Two teenagers were detained by a gang of assailants after refusing to pay $600 for a broken billiard cue smashed over their heads, a court heard. One of the victims, Wong Mei-lai, was offered the chance to repay the 'debt' by having sex with her attacker, who is still at large, prosecutor Peter Lavac told the District Court. Judge Carlye Chu Fun-ling yesterday jailed So Yiu-keung for 15 months for false imprisonment and theft. She sent Wu Ting-man to a training centre after finding him guilty of false imprisonment. So, 22, admitted the two charges, while Wu, 18, denied the false imprisonment charge. The group detained Mei-lai, 18, and her friend Kwong Kam-to, 17, after they were beaten up in Fanling. Mr Lavac told the court that on June 29 last year the two victims and their friends were confronted by a gang, including So and Wu. He said the man who is missing assaulted them with a billiard cue, which snapped. Kam-to was also attacked by the same man with a bag containing glass bottles, the court heard. The gang demanded they pay $600 compensation for the broken cue, but they refused and were taken to an abandoned house. Inside, the man who attacked them asked Mei-lai either to repay the money or have sex, the court heard. But she refused and instead surrendered her gold ring, necklace and bracelet to So. One of the victims' friends contacted the police and the next morning, So and Wu were arrested when they left the house. Judge Chu said she accepted it was not the 'worst kind of false imprisonment', but said the period of detention was not short. She said disciplinary and vocational training were important to both defendants, but So was too old to be sent to a training centre.