Nearly one month after the conversion from AT&T to Frontier Communications, more than 840 Connecticut customers have filed written complaints with the state about the changeover.

The state Department of Consumer Protection announced Nov. 13 it is coordinating complaints lodged by consumers regarding the transition. A week later, department spokeswoman Claudette Carveth said Thursday the department has received slightly more than 840 written complaints so far.

Stamford-based Frontier has been plagued by complaints ever since Oct. 25 when it converted customers who formerly had AT&T services. The change happened because Frontier recently acquired AT&T’s landline, broadband Internet, and video service operations in a $2 billion deal.

In the deal, Frontier began providing services to roughly 1.3 million Connecticut households but for many the transition did not go smoothly. Hundreds of customers flocked to Frontier’s social media pages and phone help lines to complain of troubles with their video-on-demand, TV, and Internet service.

Frontier officials have maintained that 99 percent of those impacted by the switch encountered no problems. The approximately 840 complaints filed with the state so far represent a small fraction of 1 percent of the customers who were transitioned.

State officials are urging customers who are still having trouble to contact Frontier first. But those who wants to lodge complaints with the state should do so through the Department of Consumer Protection so complaints are in a centralized place. Consumers can file written complaints online here or via email at dcp.frauds@ct.gov.

“We want to ensure that all customers are protected and adequately receiving the services for which they are paying,” Gov. Dannel P. Malloy said in a statement. “We will coordinate them (complaints) together to ensure that these situations are being handled appropriately.”

The state will coordinate with the company and any other necessary state agencies, he said. All written complaints should include customers’ contact information, billing address and the specific problem they are encountering, according to DCP.

Meanwhile, Frontier continues to work to resolve any lingering issues. Company officials continued this week to address several customer complaints posted to its Facebook page, where the company has been very responsive to consumers since the changeover.

When reached Thursday, a Frontier spokeswoman referred to a statement the company released last week when, on Nov. 13, the state Office of Consumer Counsel and the Office of the Connecticut Attorney General filed a motion for a technical meeting to be held at the state Public Utilities Regulatory Authority to discuss the transition.

Frontier’s statement says, in part, “We want to assure Connecticut customers that we are focused on providing them with prompt, quality service…Frontier recognizes that our customers have a choice in who they rely on for video, voice and Internet services, and we are committed to making sure that every resident and business in Connecticut knows that Frontier is a company that stands behind its services, products and people.”

The statement also said Frontier is cooperating with state officials as they investigate the matter. The company’s 2,500 Connecticut-based employees are working to help customers as quickly as possible, with some help from Frontier’s more than 14,000 workers nationwide, according to the company.

In addition, Frontier said it will refund more than $10 million to Connecticut customers in several ways. All 197,000 Frontier TV customers will receive a $50 credit on their bill, regardless of whether they had any service interruption or not; all 3,000 TV customers who were without service Oct. 31 through Nov. 1 will get either one month of free service or $50, whichever is greater; and anyone who experienced substantial phone or Internet service disruptions will receive a bill credit for the time they were without service.

Frontier has designated three toll-free numbers for customers to call if they are having problems. Residential customers can call 1-800-921-8101, business customers should call 1-800-921-8102 and an additional technical support line is at 1-800-219-6877.