The National Eating Disorder Association fired all six people staffing its phone-in help line and told the line’s 200 volunteers not to come back because everyone was being replaced by Tessa, a chatbot that would guide callers to sources of help.

Instead, when people called for help with an eating disorder, Tessa began doling out advice, telling one caller to cut calories, eliminate processed and sugary foods, and weigh herself weekly.

After deciding on its own to counsel 2,500 people, Tessa was suspended from duty until it can be retrained to not give individual diet advice but only to help people learn about resources.

As it turns out, the news that the six workers were dumped and Tessa would replace them came four days after the six had voted to unionize. Now the workers have filed a suit alleging unfair labor practices.