Vectren is sending out warning to some 680-thousand Indiana customers about a billing scam spreading across the nation.

Vectren Spokesperson Chase Kelley says it involves customers who get unsolicited phone calls from scam artists who claim to represent their power utility. Kelley says they warn the customers – usually senior citizens – that they’ll disconnect their service if they don’t buy a pre-paid debit card within a couple of hours and make a payment.

The victim is then asked to call back and give them the prepaid debit or credit card receipt number and PIN. The move gives the scammers access to the money in the card’s account.

Kelley says Vectren does not accept prepaid credit or debit cards and would never ask customers to buy them to make any kind of payment. Kelley adds that customers should contact customer service if they’re uncertain about any calls from people claiming to represent Vectren.

The number is 1-800-227-1376. Thus far, Kelley says no Indiana customers have reported any such calls, but she adds that other utilities are dealing with similar complaints that appear to be spreading from the east coast and toward the mid west.