A labor watchdog group has denounced Bellevue-based telecommunications company T-Mobile for what it calls “unfair and deceptive practices.”

Change to Win, a coalition of American labor unions, penned a letter for Washington Attorney General Bob Ferguson, calling on him to investigate the company.

The letter, co-signed by several Washington legislators, was released on the day of T-Mobile’s annual shareholder meeting and came a week after Change to Win filed a complaint against the company with Ferguson.

In it, Change to Win claims that T-Mobile uses deceptive advertising, unethical debt collection practices and puts unauthorized charges on consumers’ bills. The group claims the communications company has violated a 2013 settlement with the attorney general over misleading marketing. The group also claims T-Mobile has broken Washington’s Consumer Protection Act.

Several other organizations, including the Washington AFL-CIO, Center for Justice and Communications Workers of America, sent a similar request to the attorney general’s office.

These groups became involved after more than 9,000 complaints were filed nationally about the company, including 300 in Washington.

T-Mobile’s public relations department could not be reached for immediate comment. This story will be updated with the company’s response.