"Anna" will not stop calling. She really, really wants to sell you health insurance. What a lot of consumers really, really want is to smack Anna upside her robocalling head.

With health insurance open-enrollment season underway, automated phone calls offering Affordable Care Act or other health plans are spiking.

"It's at epidemic levels at this time of year," said Aaron Foss, founder of Nomorobo, who estimates his spam-call-blocking service headed off more than 850,000 health-related robocalls in October alone — nearly five times the interceptions for September.

Almost all of these calls are illegal, according to rules published by the Federal Trade Commission in 2009. Many offer plans that do not cover what you might need, regulators and consumer advocates say. Others, they say, are downright fraudulent, with unscrupulous insurance "brokers" taking payment and promising insurance that never comes through.

Alice Cave, 62, a retired data analyst from Alexandria, Va., who spends winters in Tucson, said she has gotten so many of these calls that she typically will not answer her phone unless she recognizes the number. Recently, expecting a call, she answered her cellphone.

It was "Anne." (Anna's robot cousin? Other relatives include "Jordan," "Allison" and "Mandy," although variants on Anna remain most prevalent.)

It's not all fun and games. The California Department of Insurance is investigating health insurance robocalls, said Janice Rocco, a deputy commissioner. In late August, the agency filed a court order against Health Plan Intermediaries Holdings, accusing the Florida company of deceptive and misleading practices in selling "Obamacare" plans that did not comply with the health law. The company, whose calls feature "Anne," denied responsibility.

Washington Post