The company has no right to detain your money and several valid certificates, which is illegal. You can also apply for a refund. In this case, you can ask the company to sign a labor contract with you without fixing solution.
I suggest you apply for arbitration, and you can also apply for economic compensation without signing a labor contract.
Apply for arbitration to the labor bureau where your unit is registered.
Pay attention to keeping relevant evidence.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.