What if the social security card can't be done?

First, make sure that your previous company has paid for it. Now that you have got the employment certificate, you should go through the employment formalities. You said that the account number does not exist, so you have to make sure that your account number is correct. You can check the social security code by reporting your ID number and name at 12333, and then check the social security account number. As for the social security card, if it is confirmed that there is a social security account, you can bring your ID card to the nearby labor security office or the Municipal Social Security Bureau. You don't need to go through the unit.

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