Updated

A Michigan cancer patient is fighting back after her critical claims about ObamaCare were called into question by a Democratic congressman, who went so far as to threaten Michigan television stations running her ad.

Julie Boonstra, who was diagnosed five years ago with leukemia, was featured in an ad last week by the conservative Americans for Prosperity. In it, she said her insurance plan was canceled because of the Affordable Care Act, and claimed her out-of-pocket costs are now "so high it's unaffordable."

The target of that ad, Michigan Rep. Gary Peters, subsequently had his campaign lawyers write to Michigan TV stations, effectively warning that their FCC licenses could be at risk unless they demanded more proof from AFP.

But Boonstra, in an interview with Fox News on Monday, defended her claims and blasted Peters for trying to take down the ad.

"They're not scaring me. Cancer scares me," she said. "I battle cancer every day. They're not going to intimidate me."

Boonstra's claims were first called into question by a Washington Post fact check column. Writer Glenn Kessler noted that under the law, Boonstra's premium dropped from $1,100 a month to just more than $500, and that out-of-pocket costs would be capped at $6,350. "Over the course of a year, the premium savings amounts to $6,348 -- just $2 shy of the out-of-pocket maximum," he wrote, arguing that whatever extra money she would have to pay out of pocket could be offset by premium savings.

Attorneys for Peters, who is running for Senate in Michigan, fired off letters last week to station managers citing the Washington Post column and informing them that "for the sake of both FCC licensing requirements and the public interest, your station should immediately require AFP to provide the factual documentation for its claims if you are going to continue airing this advertisement."

His team ominously cited court rulings that said failing to prevent "false and misleading" ads could be grounds for loss of license.

But AFP and Boonstra are defending the ad and the claims. Boonstra acknowledged that her premiums have been cut in half, but said the out-of-pocket expenses are unpredictable and unaffordable.

"Under my old policy, I knew what I could afford every single month because I wasn't hit with extra charges. Now I don't know what I have to pay month to month," she said. "Leukemia tests are extremely expensive."

She added: "I am not lying. ... I was lied to."