Cindy Stillwell, who lives in Bucks County, works as a part-time accountant for local businesses. So she's no slouch with numbers, and she's familiar with Internal Revenue Service protocols.

Which is why she was so upset when her 85-year-old father, Joe, who lives in Florida, wired money to someone claiming to be an IRS agent and promising him a refund of $20 million.

Yes, $20 million.

"The catch," Stillwell recalled at a recent meeting at the Metro Diner in Bensalem, "is that he had to pay the person who called from the IRS $40,000 first to get the refund."

Her elderly father had become the victim of an ongoing and terrifying IRS refund scam. In just two years, he was ripped off to the tune of six figures.

"The frightening thing? The scammers found out a lot about him once he answered that first phone call," she said. "People need to know that this happens to seniors. It's an epidemic."

After Stillwell's father, Joe, a retired fireman and top-ranked appraiser in South Florida whose last name she preferred not to disclose, began showing signs of dementia, the callers ramped up and persisted, contacting him every day and asking for more and more money for "taxes owed."

Let's stop here for yet another reminder: The IRS never, ever calls asking for money. The agency sends letters, and taxpayers are able to dispute any amount said to be owed.

The scam works like this: Fraudsters create fake phone numbers with 202  area codes that look legitimately from the IRS, which is based in Washington. The callers claim to have official-sounding titles and answering machines.

After her father sent another $100,000, this time by bank-account transfer from Wells Fargo, "a woman pretending to be an FBI agent started calling him next," Stillwell said.

The phony FBI agent, calling herself Samantha Baker, told the retiree that "she'd love to visit at his home in Florida and was attracted to older men," Stillwell said.

Her father wired another $40,000 by Western Union, this time bound for somewhere overseas.

In December, Joe traveled north to visit Stillwell for her daughter's Pennsylvania-based wedding, and his cellphone was ringing off the hook. That's when she realized Joe's scammers had gotten really clever: They had disconnected his home phone and mailed him a "burner" phone so he could take calls from them.

At that point, Stillwell said, she contacted law enforcement authorities in Palm Beach, Fla., who said they were powerless to stop the fraud. Officers told her only that they would take down her father's license-plate number, "in case he wandered off."

She was furious. Stillwell contacted the local Florida office of the FBI.  "They too, said that 'yes, it's a scam, but there's nothing we can do.' "

Finally, earlier this month, Joe again forgot that he'd already wired money. In two days, he transferred nearly $200,000 to the scam artists.

This time, the scammers claimed to be from the Federal Trade Commission, "pretending they were helping him get out from under the first ripoff from the fake IRS agent," she says.

With no help from law enforcement, Stillwell has taken matters into her own hands. She has put a freeze on her father's credit reports and his bank accounts and has even locked up some of his assets in annuities.

She considers her story a warning to others with elderly parents.

"Older people lose their friends, their careers, they're lonely," Stillwell said. "It's so, so easy for them to become the victims of scams."

She's on her way to Florida to help move her father into a retirement home — and she's getting him a new phone number.