A Long Island scam artist was sentenced to more than nine years in prison in Manhattan federal court on Friday for stealing $5.5 million from a South Korean Christian missionary school that left it struggling to survive.

William Cosme, 51, of Jericho, was convicted of ripping off the Taejon Christian International School in a 2011 investment scam, and using the money to treat himself to a 110-day Las Vegas gambling spree and a car-buying binge on a Lamborghini, a Ferrari and a Cadillac Escalade.

In a lengthy series of arguments, Cosme told U.S. District Judge Loretta Preska that prosecutors and the jury got it all wrong, and the school had failed to live up to its end of a deal in which they gave him the $5.5 million as a deposit on a promised $55 million loan that never materialized.

“There’s not even a fraud by the defendant,” Cosme said. “The defendant is actually the victim. The defendant could end up facing many years in jail, when the victim should be in jail.”

When Cosme was finally done speaking, Preska said he had lied testifying at trial, and showed his “lack of remorse” and exploitation of a naive victim through a phony website and sales pitch that portrayed him as a counselor to kings and princes who managed billions required a serious sentence.

“This is particularly so in light of the brazenness of the fraud and the grievous damage it did,” she said. “ . . . There was no justification for the offense conduct other than pure, simple greed.”

Cosme, who ran staffing and consulting businesses for 10 years according to his lawyer, was convicted in March of using a company called Cosmo Dabi International Trading Group to convince the school to wire him the $5.5 million to get a loan for a planned expansion.

He immediately began using the money for himself, the government said. The Lamborghini cost $314,000, the Ferrari $287,000, gambling losses on his junket to The Venetian in Las Vegas came to more than $200,000. He also allegedly began paying his girlfriend’s rent, and cashed checks for $415,000 and $500,000.

But Thomas Penland, the head of the Taejon school, told Preska that the scam left the school at risk of failure, with parents fearing that their tuition payments would be worthless and scholarship students at risk.

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“The damage has been severe,” Penland said. “Our whole community has been traumatized.”Prosecutor Martin Bell said more than $600,000 in a duffel bag in the back of the Escalade that was seized when Cosme was arrested had been spent by him on multiple lawyers, but asked Preska to approve a forfeiture order covering the cars and accounts with a total value of $2 million to $3 million.

In addition to a 111-month prison sentence for wire fraud, the judge also ordered $5.5 million in restitution to the school.

Penland complained that he had been told the forfeited funds couldn’t be freed up until Cosme’s appeals are over, but Bell said Manhattan prosecutors would try to expedite the process with the Department of Justice.