After investigating Time Warner Cable’s advertised claims about its broadband Internet service for several months, the office of Attorney General Eric Schneiderman concluded that the actual service delivered to customers was “abysmal” and that some of the company’s claims about Wi-Fi were technically impossible.

“What we have seen in our investigation so far suggests that Time Warner Cable has earned the miserable reputation it enjoys among consumers,” Tim Wu, senior enforcement counsel wrote in a harsh letter to Charter CEO Tom Rutledge. “Overcoming this history will require more than a name change; it will require a fundamental revolution in how Time Warner Cable does business and treats its customers.”

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Rutledge got the letter because he is inheriting Time Warner’s problems as part of Charter’s $67 billion acquisition of the company and Bright House Networks. He’s already buried the Time Warner Cable brand and will operate its networks under Charter’s Spectrum brand. The June 8 letter from the AG’s office is the latest embarrassment as Time Warner Cable disappears, following controversy over outgoing CEO Rob Marcus’s almost $100 million severance package and insensitive remarks to employees.

Time Warner had described its Internet service as “blazingly fast” and “super reliable” but the AG’s investigation found just the opposite. Large amounts of data traveling to Time Warner’s Internet customers was “regularly lost or discarded” and the performance of video services like Netflix (NFLX) was degraded, Wu wrote.

“The problems appear to have been particularly acute at primetime, precisely when many customers log on or tune in,” Wu wrote. “Customers have been frustrated, as movies freeze, websites load endlessly, and games become non-responsive.”

Charter (CHTR) plans to invest in upgrading Time Warner Cable’s network to provide greater speeds while eliminating data usage caps and modem leasing fees, a spokesman said. “Charter’s interconnection policies have been lauded by companies such as Netflix as a real benefit of these transactions for consumers,” the company said in a statement. “We look forward to bringing all these enhancements to customers in (New York) and redefining what a cable company can be.”

The AG’s office also had customers of various New York broadband providers send in speed test results. The survey found that Time Warner often failed to deliver the speeds customers were promised and failed more frequently than other broadband providers.

For more about Charter’s acquisition of Time Warner Cable, watch:

Consumers generally dislike their cable company, but Time Warner Cable has typically rated the lowest of the low in the industry. It came in dead last out of 300 companies in the the American Customer Satisfaction Index report last year, as it did in 2014.