North Adams charges that Charter Communications is guilty of "a pattern of neglect" and should pay more than $500,000 for not following through with promised fiber upgrades in the city.

The Berkshire Eagle reports those allegations were part of a letter written by North Adams Mayor Thomas Bernard to the parent company of Spectrum, which provides cable service residents in the city and across much of the Berkshires.

The letter, dated Sept. 5, outlines a number of alleged violations of the city's contract with the company.

Bernard wrote “Charter Communications has demonstrated a pattern of neglect and non-responsiveness to the issuing authority, its designees, the City, the access corporation, and subscribers,"

A spokesman for the company did not comment on specific allegations on Thursday but confirmed that Charter will submit a formal response by the Oct. 5 deadline. If the city and Charter cannot resolve the dispute, it could result in litigation.