LAS VEGAS (KLAS) — Last month, Americans received 4 billion spam calls, according to robocall blocking app YouMail.

Joanna Ganz told 8 News Now she wasn’t caught off guard when a caller identified as Chase Bank called her and said there was suspicious activity on her account.

Ganz said she was told she needed to transfer money out of her account to stop it.

“Everything he said led me to believe, because of the way he spoke and using the exact, exact verbiage the bank uses, he had it down pat,” she said.

Within minutes, Ganz was out more than $2,500.

“I really never thought it would happen to me. I mean, that’s my rent and bill money,” she continued.

Last June, the FCC required all cell phone carriers to adopt caller ID authentication technology called stir-shaken.

The goal was to prevent illegally spoofed robocalls. Since then, the number of robocalls getting through to consumers has risen back to the level it was before the regulation.

“The problem is the bad guys aren’t just sitting still. Instead of making up phone numbers, they’re getting real phone numbers. And now their real phone numbers are authenticated, they look like they’re good and they get through,” said YouMail CEO Alex Quilici.

Quilici noted that anti-robocall technology isn’t enough to crack down on spam calls.

“You want enforcement to go not only after the bad guys, but some of the carriers that are supporting them,” he said.

A spokesperson for Chase Bank said Ganz will not be refunded her money because she authorized the transfer.

Banks will never contact you to ask for your personal information.