Avista urges customers to be alert to anyone pretending to be from Avista.

"If you receive a call or email from someone claiming to be an Avista representative demanding immediate payment or mentioning that your power would proactively be shut off, immediately end the call or delete the email," according to a press release.

Avista said it never asks or requires a customer to purchase a prepaid debit card to avoid disconnection. Customers with a past due account receive an advance disconnection notification with the regular monthly billing – never a single notification one hour before disconnection.

"If you suspect someone is trying to scam you, hang up and call the local police, then Avista," the release said. "Never return a call to the phone number the scammers provide."