Why have Insurance

My elderly mother passed away in August 2017, a month before her 79th birthday. She had a revolving credit facility with Standard Bank. At the request of Standard Bank, she took out a life policy with Liberty Life. They debited her account for many years and the premiums were always paid, right up until she passed away. Naturally, we tried to lodge a claim for the small balance outstanding at the time of her death, only to be told by Standard Bank that the policy lapsed when she turned 75?? If they had notified her, my mother would never have allowed them to continue debiting her account for FOUR YEARS after she turned 75! It begs the question … if Standard Bank were diligent enough to have notified her, then why didn’t they stop the monthly premiums? I feel they were negligent and should therefore cover the claim.