Over charge of premium

I called Regent today. They debited a big amount for my December premium, when I requested clarity on it I was advised that there was a glitch in their system however refund will be done within 7 to 15 working days. My issue is that I cant wait for that long to receive my refund. I am negatively implicated and if I want to receive my refund earlier than 15 days , I need to forward them my bank statement and advise that I wont be reversing the payment. at the end I need to run around and get a statement from my bank which I will be charged for? The consultant also advised that she cant advise how much my refund is? to me this is very unprofessional that I need to wait. If I had left only limited money and the bank reverses my premiums for (Not Provided for) they would have cancelled my insurance.