A bookie and his wife were attacked in their home by two masked men who claimed they were owed a £2,000 debt, a court heard.
One of the powerfully-built thugs pinned Leonard Wainwright to the floor and his wife was grabbed around the throat.
They only left after 68-year-old Mr Wainwright promised to get the cash for them the next day, Maidstone Crown Court was told.
The boy is to appear at Maidstone Crown Court
John Paterson, 43, of Smetham Gardens, Rochester, denied conspiracy to blackmail, but was convicted and remanded in custody.
Gregory Harbron, of McKenzie Road, Lordswood, Chatham, admitted the offence at a previous hearing. They will be sentenced on a date to be fixed.
Mr Wainwright told how he was a bookmaker at Sittingbourne greyhound track when Harbron, 32, was refitting a kitchen for him and asked if he could make a betting investment.
"They attacked me and held me down. One of them got me on the ground. I felt frightened. I thought they were going to kill me..." - victim Leonard Wainwright
It was agreed Harbron would invest £3,000 and it would be doubled to £6,000. He was paid the money and he then asked to put in another £3,000 for the same return.
But Mr Wainwright told Maidstone Crown Court he lost his pitch at the dog track and he could not keep up the agreed payment plan.
He resorted to borrowing from payday loan companies that charged 450% interest and was facing eviction from the family home in Murston, Sittingbourne.
"The mortgage was not getting paid," he said. "I took out seven payday loans. I probably owe them £20,000 in total."
Mr Wainwright said Harbron would increase the amount owed if the instalments were not paid on time.
"I owed him £4,000 and I paid him £10,000," he said. "He said I still owed him £2,000."
Leonard Wainwright was a bookmaker at Sittingbourne greyhound track
Mr Wainwright was at home with his wife Susan on February 13 last year when the two heavies dressed in black and wearing balaclavas forced their way in.
"They were two big men," he said. "They attacked me and held me down. One of them got me on the ground. I felt frightened. I thought they were going to kill me. He said: 'We have come for the £2,000.'
"My wife was in the conservatory. She heard the commotion and came to see what was happening. The second man got hold of her. She was trying to push him out the front door.
"He shut the door and had her around the throat. I said: 'I will have the money for you tomorrow.' It was all I could think of saying."
The men warned them not to call the police, but they did so after they left.
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