HARTFORD, Conn. (WTNH) — About 500 complaints has triggered a state investigation into Optimum’s practices, Connecticut Attorney General William Tong announced Monday.

The investigation falls under the Connecticut Unfair Trade Practices into Altice Optimum customer complaints that the company has slow internet speeds, hidden fees and “unacceptable” technical support, according to Tong.

The investigation will look into records dating back to January 2017. Customers, Tong said, paid for 300 Mbps or 400 Mbps cable internet plans and noticed they weren’t receiving the speed they paid for. The company also had a $3.50 “network enhancement fee.”

If his office finds that the company violated the law, “we will not hesitate to hold them accountable,” Tong said in the written announcement.

“Customers deserve the services they pay for, and these allegations indicate that Altice Optimum has failed to deliver on its word for half a decade,” Sen. Norm Needleman (D-Essex), co-chair of the energy and technology committee, said in the written announcement. “As the internet has become a vital part of everyday life, households relying on these services for employment, education and entertainment can experience significant harm if they lack reliable internet service. If Altice Optimum contributed to that harm, they should face the consequences.”

“Altice shares the state’s goal of ensuring Connecticut residents and businesses receive high-quality service and have a positive customer experience,” the company said in a written statement to News 8. “That is why Altice has been investing across Connecticut, building and deploying a 100% Optimum Fiber broadband network that provides reliable infrastructure and symmetrical internet services to our communities and customers. Connecticut was one of the first areas where we launched multi-gigabit speeds earlier this year to meet the ever-growing broadband needs of our customers, and we also participate in the Affordable Connectivity Program, which provides free high-speed internet service. We are proud to serve our Connecticut communities and will cooperate with state officials to provide relevant information.”

A spokesperson for the company told News 8 that the complains date back to January 2017.

Tong’s office sent Optimum a request for detailed consumer complaints records. The investigation will look into how the company marketed internet speeds and if they knew about issues. It also wants to know how the company used the “network enhancement fee.”