Unauthorized or *****ulent debit order

I am client of Miway, last month the company debited my account as agreed with the insurance premium and few minutes after another debit order went through my account. I called Miway since to notify them about this error and requesting an explanation as to why this happened and all they could tell me was a system error. I then requested a refund of that money they claim was erroneously debited, Miway doesn't want to refund me. I have made several calls where I spoke to different consultants and all of them telling me one thing, "A refund was requested and the money will be paid, asking the so called managers to approve this refund". Giving Miway access to my account through an insurance premium was never a license for Miway to do as they pleases in my account. Miway I am demanding that money as you had no mandate to debit it.