What should I do if the social security of the last unit is transferred by others?

Very easy to handle. First of all, they can't transfer your social security. Social security is exclusive, provided it matches your identification. Even if it is turned, it can't be used. If it is transferred to you, you can sue them, including the social security department, because it is impossible to transfer your social security to others without the convenience of the social security department, and the social security cannot be taken out halfway.

It is illegal for them to ask you to pay all the money paid by the last unit for social security, which violates the labor law. You should have sufficient evidence, consult legal professionals, see what evidence needs to be prepared, and then give courtesy to soldiers.