Capitec deducted money from my account without my permission.

Hello Peter. A few days back I received money that I had to transfer to someone else, I did transfer the money as I should have. But today Capitec, Bloem Plaza branch. Deducted money from my account (Mind you the money they deducted is not mine, yes its in my account but for safekeeping, I'm talking about R3500 here) without consulting with me first. When I called Bloem Plaza Capitec the lady was rude, and she told me to go to my nearest capitec, but she didn't tell me to go to my nearest capitec when deducting the money. Cool, fast forward, I called the service provider, and they also told me that they can't help. Please help me get that money back, because as I have indicated, it's not mine.