Edmontonians are being reminded of the importance of reading monthly bills carefully – and comparing month-to-month in addition to last year’s bills - after one woman received a power bill more than four times what she typically owes.

Audrey Tremblay was shocked when she saw how expensive her September power bill was.

“I’m looking at it and I’m like $1,000 for my bill? That’s outrageous, when it should be only about $250,” Tremblay said.

Tremblay is on a contract with Just Energy, which means her electricity rate is a constant, so that wasn’t the issue.

As far as consumption, Tremblay says she didn’t use any more power that month than any other month.

“When I phoned in, they said they were billing me back to December,” she said.

Just Energy tells CTV News that Tremblay’s metre had been faulty, so EPCOR replaced it. The price listed on Tremblay’s September bill was a reflection of missed usage that wasn’t originally billed due to the faulty metre.

“Generally they’re quite reliable but when they do fail, they don’t necessarily stop. Sometimes they’ll go a little bit faster, sometimes they go a little slower,” said Tim le Riche with EPCOR.

“We don’t always know whether that’s representing a metre failure or a change of pattern of consumption in the home.”

EPCOR and Just Energy said Tremblay's bills were lower than they should have been for several months in the past, so EPCOR took an average over historical data and then adjusted Tremblay’s usage – which Just Energy then billed her for.

That resulted in more than $800 she didn’t expect to owe.

“If we do discover that the metre has failed, we replace the metre and take an average over the historical data of the customer and apply that monthly rate on that average to the bill for the period that was missing,” le Riche said.

Tremblay said the charge isn’t fair.

“I pay my bills every month when I receive them so all of a sudden this is happening, I don’t think that’s right,” Tremblay said.

EPCOR says the best way to avoid owing large amounts is to watch usage each month and call your provider if the numbers seem incorrect.

“You need to keep an eye on your bill and take a look at the consumption readings,” le Riche said.

“You know how much you’re using. You should have a feel for that and if it seems wrong, call us because we can check and eventually it will get noticed by our computer system or our metre readers and it will catch up to you and we know that’s a tough bill for people to receive.”

Tremblay said she didn’t notice any unusual bills but can’t double check, as she shreds past bills.

“It’s very frustrating. It’s very, very upsetting,” she said. “I don’t have $1,000 dollars to give them today, I don’t. I have bills, I have rent, I have groceries to buy. It’s not right to do that to people.”

After CTV News contacted Just Energy, the company followed up with Tremblay and offered her a payment plan to deal with extra charges. Tremblay said she's happy with that option.

With files from Laura Lowe