Refusing to refund money that was mistakenly paid when they no longer handling the case

I paid money over to Landau in October and November 2024. The amount adds up to R2000 which they had to pay over to Old Mutual. This amount was never paid over to Old Mutual. When i realised this in Feb 2025 i immediately contacted Landau. I have been contacting them on numerous occasions requesting that the money be paid to Old Mutual. I even sent them proof of the payments i've made. Each time i call i am given a different excuse and i am told that the money will be paid. It is now October 2025, almost a year since these payments were made and still nothing. Have they now decided to just keep money that does not belong to them?