Unfairly treated

I had a policy with Old Mutual unfortunately it happened that the policy lapse but was able to reinstate it again and it’s active. Now I have a member that died from the policy when I make a claim they telling me that I am on a waiting period. Why do I have to be on the waiting period again when I am already their client and already served the 6 months waiting period? Why are there so many waiting periods? Now they tell me that they only gonna pay out only what I paid (according to number of premiums I already paid) they say they give us up to a certain time to reinstate the policy if it passes then it becomes a new policy. This is heartbreaking really also considering that some of us insure old people who are always sick yet they want us to serve too many waiting periods!