Unauthorized debit

I'm sick and tired of this bank, they've added an amount I didn't agree on on my installment even after I've called them 3 times and emailed proof of my fully comprehensive insurance 2 times and the last time they confirmed that they received it but they still took money from my account for the insurance they took for me without my consent even after I've proved that I do have my own, I'm already going through the most and can't afford to loose even R5 from my salary, I can't be insured twice I want my money back😡