Funeral Claim Not Paid In Full

My mom has a funeral cover with Standard Bank Insurers for years, she began with the cover more 15years ago. She always made the deposits on time for the debit order. On the 27th January she called the funeral cover department to inform the about a claim as she had lost her mom. She was then informed that her claim will only pay out 80% of claim amount(80% of R6K),because she missed a month's premium . My mom never received any form of communication about her missed premium , as a matter of fact she had funds sufficient for the premium to be paid, Indeed the claim she received was R4999 instead of R6000. Standard Bank funeral dropped the ball on this one by failing to inform my mother and they could not deliver when it was her time in need. She will be canceling her policy and moving to another insurer that will be treating her better than Standard Bank