Why can't social security be paid back?

Dear you, 1. If you can't pay back, you can't get re-employment after leaving your job due to company closure or personal reasons, and you haven't applied to pay social security as a flexible employee. The above situation belongs to the social security default caused by personal reasons and cannot be repaid. 2. What can be paid back If the enterprise suspends payment or fails to pay social security for its employees due to its own problems, the enterprise has the responsibility to pay back the employee's personal social security, and the late payment fee is also borne by the enterprise.