My late mother's retirement annuity fund

I am not happy at all with old mutual and I even regret joining my annuity fund with them. My mother is late since July 2021 and when I went to claim her annuity fund they told me to send everything on the email which I did,three months later I wend to check and I was told they wanted letter of authority. We as sibling we got the later of authority where we elected my middle sister to claim everything.She went to the branch and she was told they don't see any money but they can submit which they did.Six moths later she wend to check,they said it's going to take a year.A year later she went and she was told we all need to sign the forms that even want my mother's assets.I am so confused of what is happening.Is this how Old Mutual treating their clients.CAN SOMEONE WHO IS WISE HELP US BECAUSE CLEARLY WE ARE DEALING WITH CLUELESS PEOPLE FROM FESTIVAL MALL AND THE SO CALLED HEAD OFFICE.I DONT UNDERSTAND WHY IT TAKES 2 YEARS TO PROCESS A SIMPLE CLAIM BUT IT TOOK DAYS TO PROCESS THE APPLICATION.WE WANT OUR MONEY.