From impersonating police to threatening to hurt loved ones, brazen Bulgarian gangs terrorise the elderly and rob them of their life savings with increasingly aggressive phone scams netting millions of euros.
"They did not only take my money but also my health... I keep shaking all day long," Gergina Alexieva, a retired teacher in the western town of Kyustendil, told AFP.
The 82-year-old recently fell victim to one of the most popular schemes, which involves tricking people into believing they are assisting police with catching a gang of scammers.
In a phone conversation, a man posing as a cop warned Alexieva that she was about to be contacted by criminals who would try to blackmail her into handing over her money.
He instructed her to follow their orders, saying that officers were waiting outside the house to catch the thieves in the act.
While Alexieva was talking to the alleged official on the landline, her mobile rang and as predicted, an aggressive voice shouted at her to throw her money off the balcony.
"The fake policeman on the landline told me: 'Don't worry madam... Collect everything you have -- money, gold rings -- and do as they say. Everything will be alright,'" Alexieva said.
The plot might seem implausible at first but add to that a menacing tone and many will feel too intimidated to question the scenario.
"I did as I was told... I was very scared," said Alexieva, who lost her entire life savings of 5,800 leva (3,000 euros, $3,200).
- 'Just hang up' -
Old people are easy prey in the European Union's poorest member state: many live alone because their children and grandchildren have moved abroad in search of better opportunities.
The isolation, coupled with the bitter memories from a series of banking crises, has prompted senior citizens to hide large amounts of cash in their homes.
Well aware of this, sly fraudsters work their way through the phone book and dial random numbers in the hope that an elderly person will answer.
And often they get lucky.
Around 900,000 people in the 7.4-million-strong nation have been the target of phone fraud, particularly those aged over 60, according to a new survey by Bulgaria's Trend Institute.
In the capital Sofia, a retired doctor told AFP she suffered a heart attack after being duped.
"It wasn't their lies that made me cave in, but the threat to cut off my daughter's ears," confided the 79-year-old, who wished to stay anonymous.
Bulgarian media abound with daily stories about the fake cop hoax.
Amid rampant corruption, other common phone scams include extorting money to allegedly help a relative pay for a costly medical operation or bribe a cop to avoid prosecution after killing a child in a car accident.
Between 2011 and 2016, these shakedowns netted around 11 million euros, of which almost a third accounted for just 2015.
In response, the government has launched a major awareness campaign, with state TV broadcasting ads about the most popular hoaxes and how to avoid falling prey to them.
But elderly citizens have also begun to take matters into their own hands.
Each week, locals in the southern village of Rogosh get together to discuss the latest scams and ways to respond.
"Just hang up" is a commonly shared piece of advice.
"The women here have had the courage to fight back and react without panic. No one's fallen into their trap over the past year," said mayor Velichka Velichkova.
Rogosh's anti-scam club has proven so successful that police authorities have decided to launch similar initiatives elsewhere in the country.
- Hard to catch -
Nonetheless, authorities are having a tough time hunting down those responsible.
Just one in 10 suspects is identified, according to official data.
The scammers use pre-paid mobile phone cards that make it impossible to track them down.
The con men are careful not to call each other and there is no direct contact between the gang leaders, those ringing the victims and the people collecting the money.
"Families have specialised in this scam over generations, entire neighbourhoods have been doing it since the 1990s," said a police officer, who wanted to remain anonymous.
"When we do manage to expose a network, a family member with a clean criminal record will take the fall and get off with a suspended sentence."
The scheme has proven so successful that Bulgarian gangs are now also targeting neighbouring Greece, where people have been stashing even bigger sums in their homes following the financial crisis.
Seven Bulgarian nationals were recently transferred to Greece to be prosecuted on suspicion of trying to scam 34 retired Greeks.
"If the scam yields between 2,000 and 5,000 leva (1,000 and 2,500 euros), in Greece it's between 30,000 and 50,000 euros," said senior police official Zlatka Padinkova.