First, as long as the old-age insurance has been paid for 15 years and reaches retirement age, you can receive a monthly pension.
Second, social insurance is a kind of insurance required by the state. The state develops social insurance undertakings, establishes a social insurance system and sets up a social insurance fund, with the aim of enabling workers to get help and enjoy insurance benefits in old age, illness, work injury, unemployment and childbirth. China's "Labor Law" and "Social Insurance Law" clearly stipulate that it is the legal obligation of the employer to pay social insurance for workers, which is obviously compulsory by the state, and the employer shall not refuse to undertake this legal obligation under any excuse or reason.