No pay out after two years of claim on the policy

Old Mutual has still not paid out on the policy my brother had after two years of his death. The widow has been in and out at Old Mutual for the past two years since March 2019 when her late husband died. She submitted all the required information and to date always she gets a call to come back because there is a page that was missing on her claim. This is unacceptable and the husband has passed away for two years and no pay out has been made.