Old Mutual Superfund is giving me hussles!

I am very disappointed in Old mutual. My husband passed way in March of 2019, till now Old Mutual hasn't paid his provident fund to us (me and his 4 kids). What's even more painful is every time I try to contact them they become very unhelpful and rude, saying that the case is under investigation, question is how long are they going to investigate? its been 17 months now! Their reason for this 'investigation' is my late husband's family now claims that he was taking care of them financially and that is not the case, even if it were, I am the legal spouse and have 2 kids with him, I have also acknowledged his other two kids but it seems like it's not good enough for Old Mutual Superfund to pay out whats due to me and all his children. I have supp**** them with every document they've required from me: IDs, Marriage Certificate, Letters of Authority, Death Certificate, Childrens Birth Certificates and filled in every other document they requested from me. Please help me out, this is ridiculous! I owe school and crèche fees drastically since I myself am also unemployed!

Regards, Palesa Ramohanoe