CHICAGO (CBS) — The Federal Trade Commission has estimated hundreds of millions of dollars are being collected by robocall scams, and it has sued five companies to stop the practice.

WBBM Newsradio’s John Cody reports the FTC announced Thursday it has pulled the plug on five robocall companies based in Arizona and Florida, after they allegedly scammed people out of an estimated $30 million in two years.

READ MORE: Proposed Federal Legislation Would Impose Regulations To Prevent Black-Market Brokering Of Donated Body Parts

According to the FTC, the companies would place automated calls to consumers offering “cardholder services,” with an opportunity to reduce the interest rates on their credit cards.

“They were sweet-talkers,” said 84-year-old Alyce Weisbach, of Skokie, who said she knew as soon as she provided a company called Green Savers with her personal information over the phone that she shouldn’t have done so.

LISTEN: WBBM Newsradio’s John Cody reports

“I’m savvy, and I knew what I did was wrong. And to give my Social Security number, and my mother’s maiden name was the worst thing,” she said.

READ MORE: Woodridge Residents Cope With Emotional Impact Of Damage From Sunday Night Tornado; Village Places Priority On Getting Power Back On

The FTC said Green Savers did nothing but add charges to Weisbach’s Visa bill and the credit card bills of other victims.

The agency has sued the five firms – Green Savers, Treasure Your Success, Ambrosia Web Design, A+ Financial Center, and Key One Solutions – alleging the companies misled consumers into believing their credit card rates would be reduced, saving them thousands of dollars.

In calls from those companies, telemarketers allegedly charged the victims up-front fees ranging from a few hundred dollars to nearly $3,000, claiming the consumer would see greater savings on their credit card bills through lower rates. In some cases, the companies allegedly did not disclose the up-front fee at all.

However, consumers saw no savings on their bills, and often found it difficult – if not impossible – to get a refund of the fee they paid.

MORE NEWS: Residents Repairing Homes After Tornado Run Into Sky-High Prices For Lumber, Other Construction Materials

The FTC offered a $50,000 prize for the best plan to block illegal robocalls on land and cell phone lines.