A mother bought an AIA Guardian Basic policy for each of her three children in 1992. She was told, or led to understand, that each policy would mature when her child reached 21 years old. After 20 years, she was shocked to learn that the actual maturity date for each child was on they reach aged 101.
She could not remember what had happened. She did sign the papers in 1992 but did not make any change to the policy. She remembered that during the financial crisis, she might have blindly signed some papers provided by the insurance company. Her son asked me for my views.
From your description, it seemed that your mother had bought a whole life policy for each of the children. If you do not wish to pay the premium, you can ask for the policy to be made paid-up for a reduced sum assured, or to be terminated for a cash value.
I do not have any comment about any possible misunderstanding between your mother and the agent on the duration of the policy. It is quite risky for consumers to commit to a long term contract, such as a life insurance policy, without proper understanding of the terms of the contract, relying only on the vague explanation of the agent.
You should write to the insurance comapny to ask if the policy was issued on these terms, or had been changed during the past 20 years. It is quite likely that the policy was kept at the original terms, and that your mother had misunderstood the maturity date. The agent might have told her that she can stop paying the premium at age 21, by using the accumulated bonus to fund future premiums. But, as the bonus was cut during the financial crisis, the accumulated premium was not able to fund the future premium.