1. First of all, you have to prove that you have a labor relationship with the employer. It is better to have a labor contract. If not, the following things can also prove the existence of labor relations between you.

If the employer has not signed a labor contract with the employee, it may refer to the following documents when determining that there is a labor relationship between the two parties:

(a) payment vouchers or records (payroll), the payment of various social insurance premiums;

(2) Work Permit, Service Certificate and other documents that can prove the identity issued by the employer to the employee;

(3) Employment records such as Registration Form and Application Form filled out by employees.

(4) attendance records;

(5) Testimonies of other workers, etc.

Among them, the relevant documents in items (1), (3) and (4) shall be borne by the employer.

2. Then inform them of your complaint request, and it is best to attach relevant evidence that can prove your reasonable appeal.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.