Family certificate and insurance claim

My husband died after 6months of marriage and no children for us. his parents divorced and father got remarried twice and owns company mother is single.husband was raised by his grandparents his grandma gets pension of 40k. As per to process insurance and PF his company requested certain documents. When I went to meseva they told that me and my children will be included in family certificate his parents cannot come under dependants as they are earning. But my father in law sent notice to his company saying the certificate I made has disputes as i didnt include them i.e his name, his 3rd wife name and grandma and them to stop insurance claim. Also he said he needs 50% of claim as he has legal rights warned company not to claim in my name if they do he will file case. He made death certificate of his son without my name in it when questioned he told meseva persons didn't add my name by mistake also he went against people who did family certificate to cancel that to remove mine and add theirs. He even shouted at them to change his birth mother name in his death certificate to his present wife name as my mother in law requested her share in what my fatehrin law gets as am mother to him. What should I do did I do wrong, that I didn't include them in family certificate, actually I didn't knew about that much I did as they told to do in mro office