John Johnson, 43, and Stephen Whitehouse, 48, kicked and punched their victim – who suffers with mobility issues having only one leg – as he lay on the ground.
Derby Crown Court heard both defendants had known their “easily-led” victim for a “considerable period of time” and all three would take drugs together.
However prosecutor Raglan Ashton said the vulnerable victim told the council’s housing department that he was “sacred” of the defendants and he wanted to move.
Johnson and Whitehouse had previously raided their victim’s bank account after he gave them access to buy drugs.
The May 14 assault came about after the pair discovered PCSOs had visited their victim’s home at the request of the council – who were concerned for his welfare.
He later told Johnson he had reported the theft of the money from his back account.
Mr Ashton said: “A short time later Mr Whitehouse phoned (the victim), asking him to meet him at the local park – he said Mr Johnson was in trouble and had been arrested.
"At the park Mr Whitehouse became aggressive and asked (the victim) what he had in his pockets – (the victim) emptied his pockets and handed over his mobile phone and £85.”
Moments later Johnson came from behind and the attack began.
Mr Raglan said Johnson “snuck-up” behind the victim and hit him to the ear with an open palm “numerous times” – making him scream and perforating his eardrum.
The victim was also kicked to the ribs and Whitehouse placed his hand over his mouth to silence him and Johnson pulled out a pair of rose pruners – placing his victim’s fingers between the blades.
While various threats were made – with Whitehouse telling him: “You do realise we’re going to bury you.”
Johnson also pulled out a knife and threatened to stab the terrified victim with it.
Mr Raglan said once the assault had come to an end both defendants walked with the victim as he managed to get to his feet.
However when he fell to the floor Johnson “brandished” a knife and told the victim he had “better get up”.
The victim was eventually taken to hospital after losing consciousness when police attended his flat.
Judge Martin Hurst told the pair: “I have no doubt at all most of this attack was caused by an irritation that he (the victim) had got the authorities involved.
"You were worried you would be in trouble and remanded and would not be able to get your drugs anymore.”
He told Johnson: “You hit him very hard in his ear – causing the major injury in this case. You perforated his eardrum. You caused the violence."
Judge Hurst said he had “no doubt” it was a joint attack, adding: “Mr Whitehouse, you held your hand over his mouth – that would have been extremely frightening.
"But the principal violence was used by you, Mr Johnson – you attempted or pretended to cut his finger off and held out a knife, threatening to stab him.
"He was in such a state he had to be taken to hospital.”
The court heard both defendants had been jailed previously however Judge Hurst noted Johnson’s record was the worst by “a considerable distance” – an “aggravating factor”.
Johnson had been jailed nine times since 1998 – having most recently served 10 weeks for shop thefts in May.
Johnson, of Cordwell Close, Staveley, admitted GBH and was jailed for 27 months.
Whitehouse, of Bond Street, Staveley, pleaded guilty to GBH and was jailed for 18 months suspended for 18 months.
He was handed 150 hours unpaid work, 30 rehabilitation days and a 30 day programme requirement.