My dad didn't have joined Old Mutual

We are truly saddened by how Old Mutual pension fund has been harassing my family throughout this past year.My father passed away on the 7th of November 2021 and till this day we have been harassed by Old Mutual.When my father passed away we received a call from one of the investigators asking us about children that we don't know.A thorough investigation was made and none of those kids were found and the case was closed.My mother and us as siblings received a lump sum from Old Mutual that ddnt make sense to us.We sent an email requesting a statement regarding the money that we received as nominated beneficiaries and till this day we haven't received anything from them regarding the matter, a few months ago my mother received a call again from an investigator asking about another child that we don't know and was very disrespected by the investigators wanting her to admit to something she doesn't know.Again we requested the statement and asked for DNA tests to take place but there was no response or whatsoever from them.Few weeks later my mom received a letter from them stating that she needs to pay that alleged child a lump sum from her money whereas there was not even proof of anything.Today my sister and I both received calls from Old Mutual asking us about 3 kids that were investigated just after my dad passed away and once again we were being harassed by the guy over something we don't know.We asked them for how long are we going to be harassed over this matter.We asked them for the statement again and we couldn't get answers,asked them what happened to the matter of the child they were talking about a month ago and the guy simply said they sorted it out.How do they sort out a matter over hearsay because there were no DNA tests that were conducted and there was no proof of anything.We are deeply hurt on how they have been harrasing us and tormenting my mother who is a widow.We have never found peace since my dad has passed away, we haven't even had time to grieve because they have been harrasing us...We really need help right now because this issue is really getting out of hand!!!+