Provident fund claim

My sister was working at Simba Kempton Park and past on the 24th July 2024.i am writting this with a heavy heart as we are struggling as a family to take care of my late sister's children. I have been sending emails to the lady of HR, but I am not getting any response from her. She is not taking my calls. We don't know who can assist us ragarding my late sister's provident fund claim.