(Reuters) – The chief executive of CenturyLink Inc said he disagrees with claims made by the Minnesota Attorney General of not cooperating with the investigation related to a lawsuit on overcharging for internet and cable services.

In an email sent to company employees on Thursday, Glen Post said he does not agree with the attorney general’s claims of being “uncooperative” pertaining to the ongoing investigation. The email statement was seen by Reuters on Friday.

The lawsuit, filed earlier this month, alleges CenturyLink often refused to honor the lower prices customers had initially been given by sales agents, saying that they were misquoted or did not qualify for promotional discounts.

“We take these allegations very seriously and are diligently investigating them,” Post said in the email.

The telecommunications company said it has hired law firm O’Melveny & Myers to conduct an independent review.

As at the last close of $23.37, shares of the company have fallen 2.4 percent year-to-date.