Horror old Mutual

I am very disgruntled with old mutual provident fund , there are nothing but ****** ****mers . My grandfather passed away in 2004 while working for ****rnet is is now Transnet and chose old mutual to keep his provident fund for the loved one .Little did he know that old mutual is the company you cannot trust with your money . After his passing my grandmother has been receiving the money from them roughly R1500 every month which still this was not enough knowing how many years and how much he was getting paid . For the past 3 years now old mutual decided to cut my grandmom pension salary to R400 without any explanation or anything . This is a day light ******* .I phoned them last week and i was told the money dropped because the market valley dropped ( what the hell ) and my grandmom chose that percentage during her anniversary and this is nothing but a lie , i was the further told that her money was kept by Liberty scheme before but failed to provide me with the prove supporting their statement how ever i was told that investigation will be done to what really transpired . I cannot wait while i can see that my grandmom is dying of heart attack because of horror old mutual . All what i need is the answers on what happened to my grandfather provided fund. How do one say we communicated with her with the changes but no proof . For the record i am talking about a person who was born in 1948 with no or little understanding of market value or what so ever .With this being said i am ****ed off to the core and i need a proper investigation to be done and I need feedback asap