Death claim for my late sister with Nbc

Hi there, I would like to be helped in claiming my late sister's provident fund. She passed away in 2010 and left a baby boy who was almost 1 year old then. I have been backwards and forward with Nbc in Cape Town. They wanted all documents and I forwarded everything last year November. I have been in contact with a lady by the name of Joane in the cape town branch, she keeps on promising me that she will get back to me since last year and she doesn't at all. Even yesterday I called and she said I must give her few minutes and she will come back to me but as usual she didn't. Can someone please help. My late sister has worked +- 10 years . She left a son who needs the money and we do not know the whereabouts of the father of the child.

Kind regrds Thantaswa Ngalo ********** 486