Two brothers have been sentenced to 20 years for preying on the elderly, charging them exorbitant fees for shoddy roof work, DeKalb County authorities said Tuesday.

Keith Ogles, 50, of Jonesboro, and Jeffrey Ogles, 52, of Griffin, who pleaded guilty to financial exploitation of the elderly and home repair fraud, must serve 10 of the years in prison and pay $100,000 in restitution.

Not only did the brothers grossly overcharge four seniors for the work they did, authorities said, they damaged their roofs. One of the victims also was threatened when he refused to make additional payments, the authorities added.

"This pair deliberately preyed on elderly victims, who were all in their eighties, and demanded payments that reached over $130,000," DeKalb County District Attorney Robert James said. "This was a calculated scheme that targeted and exploited elderly homeowners."

One victim was an 89-year-old woman who suffers from short-term memory loss. Atlanta police said the brothers charged her over and over because she couldn’t recall them ever doing the work. She ended up paying more than $40,000 for a job that should have cost less than a $1,500.

Wells Fargo tipped authorities to the problem last November. The 89-year-old woman tried to withdraw $16,000 in cash from the bank, explaining she had to pay one of the brothers who was waiting for her in the parking lot. Atlanta police fraud investigators uncovered the overpayment.

In another incident, an 85-year-old man was told he needed repairs even though he already had a new roof. He paid the Ogles $72,000, authorities said.

The man paid “for work that did not need to be done and which was worth approximately $1,500,” said Jeanne Canavan, the deputy chief assistant district attorney who oversees the Elder Exploitation Unit in DeKalb.

“When the victim tried to refuse further payments, the Ogles told him that if he didn’t pay, their company would tear up his roof,” Canavan said.

The other victims in the case, authorities said, were an elderly couple who paid the Ogles brothers more than $20,000 for roofing work that was later valued at only $2,000. They returned on numerous occasions without invitation or appointment, each time asking for additional payments, according to authorities.

On Nov. 24, 2014, the couple came home and found the Ogles on the roof, uninvited. The couple called the police and the brothers were arrested at the scene.

“We all have to be vigilant in making sure that our parents and grandparents are not being taken advantage of and exploited by criminals like the Ogles brothers,” James said.