Thomas Birkert, an 18-year-old A-level student was kidnapped near his home in Chelsea, west London, and was repeatedly battered around the head during his four-day ordeal.
Sentencing Jay McConnell, 17, and Emmanuel Francis, 20, at the Old Bailey, Recorder Oliver Sells said: "This was not a case of schoolboy bullying which got out of hand. His period of detention must have been as terrifying for him as it must have been for his family."
McConnell, who had been high on drugs and alcohol, had no regard for the schoolboy's suffering, Recorder Sells said, and appeared to relish it. His attitude towards his fellow teenager had been "chilling," said the judge.
"Your behaviour belies your years. You have shown you are capable of enforcing your will on a boy who although much the same age, came from a different and more sheltered background."
He jailed McConnell, of Chelsea, for four and a half years and Francis, of no fixed abode, for three years for false imprisonment, robbery and blackmail. As he was led away, a swaggering McConnell smiled at the public gallery.
Their victim, who had been reduced to a "zombie-like state" during his ordeal last November, had given evidence along with his parents at the trial in July, but none of the family were in court for the sentencing.
Recorder Sells said the public "rightly" expected such offences to be punished with a custodial sentence.
The pair made Mr Birkert buy them designer clothes, cigarettes and bottles of champagne and ordered him to drive them five times along the M3 to Portsmouth so McConnell could see a girlfriend.
Mr Birkert was intimidated with an air rifle and iron and battered round the head repeatedly while at the mercy of his tormentors.
He was only rescued after he was made to call his mother to ask her to bring more money to a rendezvous to meet their further demands.
Mrs Amanda Birkert immediately alerted police. She was commended by Recorder Sells for her "determination to get the police to take this matter seriously."
Although her son was rescued, his ordeal was not over. McConnell and Francis pleaded not guilty, claiming Mr Birkert had volunteered to go with them, after deciding to taste life on a very different social level to his own.
The schoolboy was forced to relive his experiences at their hands all over again by giving evidence in court.
He faced a barrage of slurs on his character during the trial. The defence claimed he had "played the rich boy, trying to buy friends" while rebelling against a strict mother and a middle-class background.
McConnell accused Mr Birkert of taking drugs, quaffing champagne with them and acting as a hanger-on. "If he wanted to have gone off home, he could," he told the court.
Mr Birkert said the claims as rubbish and said he had felt total joy when rescued. He did not take drugs, smoke, or drink and had more than enough friends of his own to have wanted their company, he said.
Since the trial he has passed his three A levels - but not at the grades he had hoped. He is due to start a degree in French and management next week.
A pupil at Emanuel School, Wandsworth, south-west London, Mr Birkert lived with his mother and grandmother. His parents had separated.Reuse content