PORTLAND, Ore. -- A nationwide text messaging scam that aims to trick cell phone users into handing over their bank account information has swept the country in recent weeks.

Scott Helmers, who lives in southeast Portland, said he recently received the text message that read: "Due to unusual activity, your Visa account has been closed."

Helmers thought the bank made a mistake and accidentally shut down his debit card and bank account.

"I didn't understand how they could close that account since it was my money. My hard-earned money," Helmers said.

Helmers called the number in the text message, 888-780-5082, for the Visa security alert. A recording asked him for his card number.

"On the phone, they wanted me to key it in, so I did," Helmers said.

Helmers said he then entered his personal identification number.

"I did so, and immediately, it said 'Thank you very much,' and disconnected," Helmers said. "Right then, I was like, 'What just happened?'"

Thousands of people across the United States have received the same text message and some have called the phone number just like Helmers. The victims have reported fake charges on their Visa cards and others have had their accounts cleaned out.

Because the scammers use phone numbers for just a few days, it's difficult for investigators to track them down. Consumer experts recommend never responding to text messages and always calling the bank first.

Experts have warned that the scammers often send the messages on Friday so they can use the bank account information over the weekend.

The Federal Trade Commission has taken control of some of the phone numbers used by the scammers in hopes of getting the word out about the scam. The following message is heard after dialing those numbers:

"The telephone number you have just called has been disconnected because it may be involved in a scam. No matter how real it seemed, that message was a trick. Once scammers have that, they can use that for identity theft or fraud."

Helmers called his bank immediately after giving the scammers his PIN. The bank put a block on his account and was issued a new card and PIN.

"They got nothing, because I caught it so quick," Helmers said.

He worries others could fall for the same scam and hopes his warning will save them the trouble.

"Just watch out," Helmers said. "Be aware."