Hydro One CEO Carm Marcello is apologizing to customers who have received poor service.

The CEO of Hydro One is issuing an apology to customers, after thousands have complained about erratic billing in the last 10 months.

Many people from Sudbury and across the region contacted CBC in Sudbury with stories of no bills, multiple bills and skyrocketing bills.

Sudbury retiree Madeleine Fex-Tinkus said she dipped into her savings to cover an unexpectedly large bill.

Pearl Pennell in South River found five bills in her mail — all dated the same day — for different amounts.

In Sudbury, Shelley Fox said she is still trying to figure out the actual amount she owes based on a string of bills that don't appear to make sense.

Now the CEO of Hydro One is saying he's sorry and pledging to do better.

Carm Marcello said the problems started with the switch to a new billing system last May.

“We've been working out some of the bugs,” he said.

“A few of the problems — the more complicated ones — have gotten away from us and now we're doubling down on solving those problems.”

Marcello said people who have overpaid can ask for their money back, and no fees or interest will be charged if Hydro One has made a mistake.

For those who owe money to Hydro One, there is a plan for gradual payments, he said.

The company is working with the Ontario Ombudsman to clear a backlog of complaints that number more than 4,000.

Marcello also said Hydro One’s customer service has not been up to par, and the company is working aggressively to make things right.

“We've already started implementing these new policies and we're hoping to turn it around from there,” he said.