An elderly woman was left £400 out of pocket when she agreed to £10 worth of work by cowboy builders.
The 85-year-old had agreed to hand over £10 to have weeds cleared from her guttering when she was cold-called at her Sunderland home by the scammers last April.
But Newcastle Crown Court heard the pensioner ended up paying out £400 for "inadequate and unwarranted" roofing work, and even had £240 of the cash "forcibly removed" from her purse.
Liam Gascoigne, 24, of Welldeck Road, Hartlepool, and Kieron Robinson, 26, of no fixed address, both admitted conspiracy to defraud and have each been sentenced to 16 months behind bars.
Mr Recorder William Lowe QC said it was a "despicable offence" but that he was bound to follow sentencing guidelines.
He told the pair: "You took advantage of her.
"Some may think this is wholly inadequate for what happened and I would not blame people if they did."
Prosecutor Victoria Lamballe told the court the victim was interviewed by the police about her ordeal but gave a confusing account due to her "age and ailing health".
The court heard the pensioner was visited at home on two separate days and she believes four men may have been involved.
Miss Lamballe told the court: "She said one had a distinctive missing front tooth, that was Gascoigne.
"In the property, one of them took her purse and forcibly removed £240 cash from it.
"The crown cannot say which defendant that might have been."
The court heard the police got involved when the pensioner told her son what had been happening.
Detectives drafted in a surveyor, who said the limited work that was done was "unsatisfactory".
Miss Lamballe added: "His conclusion was the charges were excessive, given the inadequacy of the work and the unwarranted work.
"The crown say this was deliberate targeting of a victim because of her vulnerability."
The court heard Gascoigne, who is currently serving a five year sentence for an attack on a woman, has a previous conviction for a similar building scam on a elderly man, where £1,500 was taken.
Defence barristers said both men, who have criminal records, admitted their guilt, which meant there was no trial where witnesses would have to give evidence.