Labor Contract Law Article 82 provides that the employer from the employment of more than one month less than one year, shall pay double wages to the workers each month

The employer violates the provisions of this law does not enter into an open-ended labor contract with the workers, from the date of the open-ended labor contract shall be entered into to pay twice the wages to the workers each month

The employer is not in violation of the provisions of this law to enter into an open-ended labor contract with the workers. Pay double wages

You've been working for seven years, but you didn't sign a contract, it's perfectly possible to claim double wages from the company, but it must be within one year of resignation