Overcharged!!!

My Husband has been overcharged on his monthly fee for his vehicle! A full R600 over more than 6 months! R3600 in total that was taken from us! We first didn't notice until my husband missed a payment and they told him how much was due. He asked them why so much and to his surprise Wesbank took out extra insurance on his car without any notice to us! They said they saw he was not insured which was far from the truth seeing that he had to hand in proof that he was before they financed his car!! We have now been struggling with Mpho who has promised to sort this out! It has been more than 2 weeks and we have yet to receive any payback for the amount wrongfully debited from our account!!! He actually sent us an email today saying that it is not his job to sort this out! HOW DOES THAT WORK! You can take money from us but when it comes down to paying us back it is NOT YOUR PROBLEM it seems. We would like to sort this out ASAP before we take it further on our side!!!