Outsurance, where is my money

Earlier this year my dad past away. He had an annual building policy with Outsurance. The estate is obviously still is progress. We changed the insurance to my mom’s name and wanted to change the policy to monthly. Outsurance told me that we must first pay the annual premium and after that we can change it to monthly. They will then refund the annual premium. As my mom do not had that amount of money in her account I gave them my bank’s account no. I mean, they are going to pay back the annual premium. It was confirmed several times that the monthly DT order will be deducted from my mom’s account and the annual one will be refunded into mine. The premium (over R5000) was deducted on the 14th of June 2021. I phoned the next day that they changed it to monthly and they took the monthly amount from my mom’s account. When I received no refund (18/6/2021) I asked them about it and they told me that they haven’t received the money in their account yet. I need to send a bank statement for proof that the money was deducted. We do not have an FNB in our town so I send the transaction history of the account and the DT order confirmation to Shena Leyds. They told me that they cannot work with that. I phoned for the third time yesterday and Trevor confirmed that the money is in their account, but now they need bank statements from me and my mom before they can pay me back the money. WHY? They deducted the money from my account (and I did not had to send them a statement for that before the time) and it is paid to them. Obviously after numerous phone calls I have had it. They are sitting with my money on which they get interest on and I have to run around to get it back. Trevor told me they will not pay me interest with the refund. He would contact Shena (manager) and let her phone me back (that was 24/6 at 12:56). It is now almost 24 hours later and nobody has contacted me yet.