Discovery insure Stole R3900 from my account.

Discovery insure billed my account R4915 on the 25/03/2015 for insurance on a single vehicle, i spend more than 2 hours of my own airtime over 2 weeks to try and get the money back. i keep phoning at my expense, just to get my own money back--and am told to send proof of my quotation agreement to [Email Removed] time they say there was a technical error and my account is in credit with R3900, and each time i say \your technical error has nothing to do with me