Refund the funds taken without my consent

An authorized debit order is deducted every month by Hollard. I never gave consent or approval for this. I went to one of their branches in Southgate and was told that they can see the amounts, but unable to help me and referred me to the call centre. I tried calling the call center to no avail and sent an email to their complaints department two weeks ago. I have sent three follow up emails for an update and received no response.